SARS-cov-2 protein-derived peptide and vaccine containing same

Abstract

The present invention provides a SARS-CoV-2 protein-derived epitope peptide capable of inducing cytotoxic T cells. The present invention also provides: a polynucleotide coding for the peptide; an antigen-presenting cell presenting the peptide; a cytotoxic T cell (CTL) targeting the peptide; and a method for inducing the antigen-presenting cell or the CTL. The present invention further provides a composition or a pharmaceutical composition containing the foregoing as an active ingredient. Furthermore, the present invention provides a method for treating and / or preventing the coronavirus infectious disease, and / or a method for suppressing worsening of the disease, using the peptide, the polynucleotide, the antigen-presenting cell, the cytotoxic T cell, or the pharmaceutical composition according to the present invention. Also provided is a method for inducing an immune response to a coronavirus infection. Also provided is a method for checking the history of a coronavirus infection by detecting a TCR sequence in a target.

Description

Peptides Derived from SARS-CoV-2 Proteins and Vaccines Containing the Same The present invention relates to the field of bioscience, more specifically to the field of prevention of viral infectious diseases. In particular, the present invention relates to novel peptides effective as preventive vaccines for infections, methods for preventing and / or treating infectious diseases using such peptides, and pharmaceutical compositions containing such peptides. This application claims the benefit of Japanese Patent Application No. 2021-382, filed on January 5, 2021, International Application No. PCT / JP2021 / 017162, filed on April 30, 2021, and US Provisional Application No. 63 / 236,927, filed on August 25, 2021, the entire contents of which are incorporated herein by reference. The respiratory infectious disease (Coronavirus Disease 2019: COVID-19) caused by infection with the novel coronavirus (Severe Acute Respiratory Syndrome Coronavirus 2: SARS-CoV-2) has spread worldwide since it was first reported in Wuhan, China. According to a report by the World Health Organization (WHO), as of December 2020, the number of infected people exceeded 70 million, and the number of deaths exceeded 1.59 million. Furthermore, as of April 2021, the number of infected people exceeded 120 million, and the number of deaths exceeded 2.8 million. Although vaccination is an effective means of suppressing the spread of infection, vaccines against COVID-19 are also being put into practical use. It has long been known that the BCG vaccine has a preventive effect against infectious diseases other than tuberculosis. Recent studies have also reported that the results of BCG vaccination in elderly people aged 65 years or older showed an inhibitory effect on the incidence of infectious diseases (Non-Patent Document 1: Giamarellos-Bourboulis EJ et al., Cell 2020, 183(2):315-323.e9). Furthermore, an association has been suggested between the suppression of the fatality rate or the increase rate of the number of deaths in COVID-19 and BCG vaccination (Non-Patent Document 2: Toyoshima Y et al., J Hum Genet 2020, 65(12):1075-1082; Non-Patent Document 3: Berg MK et al., Science Advances 2020, 6(32):eabc1463). In the human defense mechanism against virus infection, first, the innate immune response centered on immune cells (macrophages, NK cells, neutrophils, etc.) takes place, and then an antigen-specific immune response by acquired immunity (humoral immunity and cellular immunity) centered on B cells and T cells occurs. After BCG vaccination, the transcriptional activity of inflammatory cytokines in immune cells is promoted, and when infected with a virus in that state (trained immunity), inflammatory cytokines are rapidly released in the living body. As a result, it is presumed that the humoral immune response by activated B cells and the cellular immune response by T cells suppress the growth of the virus (Non-Patent Document 4: Netea MG et al., Cell 2020, 181(5):969-977). The spike protein plays a central role when SARS-CoV-2 invades human cells (Non-Patent Document 5: Hoffmann M et al., Cell 2020, 181(2):271-280). Many of the currently ongoing COVID-19 vaccine research and developments, including the mRNA vaccine "BNT162b2" approved in the UK and the US, are mainly aimed at inducing neutralizing antibodies against the spike protein of SARS-CoV-2 (inducing humoral immunity) (Non-Patent Document 6: Jeyanathan M et al., Nat Rev Immunol 2020, 20(10):615-632). However, mutations in the viral genome can occur as SARS-CoV-2 repeats its replication. If a mutation occurs in the gene encoding the spike protein, the neutralizing antibodies induced by the vaccine may become ineffective. In addition, studies on recovered COVID-19 patients have suggested that the duration of neutralizing antibodies induced in the human body may be short (Non-Patent Document 7: Ibarrondo FJ et al., N Engl J Med 2020, 383(11):1085-1087; Non-Patent Document 8: Long QX et al., Nat Med 2020, 26(8):1200-1204). Therefore, there are still challenges in vaccine development aimed at inducing humoral immunity by neutralizing antibodies. Cell-mediated immunity by T cells is also extremely important as a defense response against infectious diseases. Cytotoxic T lymphocytes (CTLs) are CD8-positive T cells and are induced by the presentation of viral antigens (epitope peptides derived from viral proteins) by dendritic cells (DCs). Subsequently, they recognize the epitope peptides presented on the human leukocyte antigen (HLA) class I molecules expressed on the surface of virus-infected cells and kill the virus-infected cells. By this action, the infected cells, which are the sites of viral particle replication, are destroyed, and as a result, viral growth is suppressed. Compared with neutralizing antibodies, which mainly inhibit the infection of newly formed viral particles to cells after replication, the action of CTLs, which target the viral particle replication process itself, can be said to have a more direct effect in preventing viral growth. Therefore, CTLs are thought to play a role in eliminating viruses from the body and suppressing the aggravation of infectious diseases. A report that a significant decrease in CD8-positive T cells was observed in the peripheral blood of severe COVID-19 patients compared with that of healthy individuals suggests that CTLs are an important factor for suppressing the aggravation of COVID-19 (Non-Patent Document 9: Zheng M et al., Cell Mol Immunol 2020, 17(5):533-535). Also, a part of CTLs is known to remain in the body for a long time as memory T cells. In 2003, SARS-CoV epidemic occurred, infecting more than 8,000 people. Seventeen years later, CTLs against SARS-CoV were still detected in the blood of recovered patients (Non-Patent Document 10: Le Bert N et al., Nature 2020,584(7821):457-462), suggesting that CTLs against SARS-CoV-2 may also remain in the body for a long time after being induced. Therefore, a vaccine aimed at inducing cellular immunity could be an effective preventive measure against COVID-19. It is thought that CTL induced by a vaccine consisting of epitope peptides derived from SARS-CoV-2 proteins remains in the body as memory T cells and rapidly exhibits cytotoxic activity against virus-infected cells after SARS-CoV-2 infection, leading to suppression of the progression of severe COVID-19. Therefore, identification of epitope peptides derived from SARS-CoV-2 proteins that can induce CTL in the human body is desired. Epitope peptide candidates determined based on bioinformatics have been reported, but whether they actually bind to HLA and have CTL-inducing ability has not been verified, and the identification of epitope peptides has not been achieved. (Non-Patent Document 11: Grifoni A et al., Cell Host Microbe 2020, 27(4):671-680; Non-Patent Document 12: Crooke SN et al., Sci Rep 2020, 10(1):14179). In addition, in taking measures to prevent the spread of SARS-CoV-2 infection, it is important to accurately grasp the infection history of each individual. Currently, antibody testing is the mainstream method for examining the infection history. However, antibody titers may be very low in asymptomatic individuals or those with only mild symptoms (Non-Patent Document 13: Marchi S et al., PLoS One 2021, 16(7): e0253977; Non-Patent Document 8: Long QX et al., Nat Med 2020, 26(8): 1200-1204). Such facts may pose limitations to antibody testing, and new testing methods are desired. In addition to humoral immunity centered on antibodies, cell-mediated immunity centered on T cells also plays an important role in virus infection control. Cytotoxic T lymphocytes (CTLs) recognize virus-derived peptides presented on major histocompatibility complex (MHC) class I molecules on the surface of virus-infected cells through T cell receptors (TCRs), and then damage the virus-infected cells. The T cell response to virus infection is thought to appear as a significant increase or decrease in specific TCRs in a comprehensive analysis of TCRs derived from T cells in peripheral blood. TCRs derived from SARS-CoV-2-specific CTLs may be important markers for understanding SARS-CoV-2 infection. Giamarellos-Bourboulis EJ et al., Cell 2020, 183(2):315-323.e9Toyoshima Y et al., J Hum Genet 2020, 65(12):1075-1082Berg MK et al., Science Advances 2020, 6(32):eabc1463Netea MG et al., Cell 2020, 181(5):969-977Hoffmann M et al., Cell 2020, 181(2):271-280Jeyanathan M et al., Nat Rev Immunol 2020, 20(10):615-632Ibarrondo FJ et al., N Engl J Med 2020, 383(11):1085-1087Long QX et al., Nat Med 2020, 26(8):1200-1204Zheng M et al., Cell Mol Immunol 2020, 17(5):533-535Le Bert N et al., Nature 2020, 584(7821):457-462Grifoni A et al., Cell Host Microbe 2020, 27(4):671-680Crooke SN et al., Sci Rep 2020, 10(1):14179Marchi S et al., PLoS One 2021, 16(7): e0253977 The present invention provides an epitope peptide selected from peptides derived from four structural proteins and six non-structural proteins of SARS-CoV-2 (reference sequence: GenBank accession number MN908947 (SEQ ID NO: 16)), which binds to HLA-A * 02:01 and exhibits CTL-inducing ability. Also, an epitope peptide that binds to both HLA-A * 02:01 and HLA-A * 02:06 and exhibits CTL-inducing ability is provided. Furthermore, an epitope peptide that binds to both HLA-A * 02:01 and HLA-A *Provide an epitope peptide that binds to either of 24:02 and exhibits CTL-inducing ability. Furthermore, HLA-A * 02:01, HLA-A * 02:06 and HLA-A * Provide an epitope peptide that binds to any of 24:02 and exhibits CTL-inducing ability. The four structural proteins specifically refer to the following proteins: Spike protein (Reference sequence: GenBank accession number QHD43416 (SEQ ID NO: 17)); Envelope protein (Reference sequence: GenBank accession number QHD43418 (SEQ ID NO: 18)); Matrix protein (Reference sequence: GenBank accession number QHD43419 (SEQ ID NO: 19)); and Nucleoprotein (Reference sequence: GenBank accession number QHD43423 (SEQ ID NO: 20) On the other hand, the six non-structural proteins specifically refer to the following proteins: ORF1ab (Reference sequence: GenBank accession number QHD43415 (SEQ ID NO: 21)); ORF3a (Reference sequence: GenBank accession number QHD43417 (SEQ ID NO: 22)); ORF6 (Reference sequence: GenBank accession number QHD43420 (SEQ ID NO: 23)); ORF7a (Reference sequence: GenBank accession number QHD43421 (SEQ ID NO: 24)); ORF8 (Reference sequence: GenBank accession number QHD43422 (SEQ ID NO: 25)); and ORF10 (Reference sequence: GenBank accession number QHI42199 (sequence number: 26)) The epitope peptide of the present invention can induce a specific and strong immune response against COVID-19 in HLA-A24:02 positive individuals with a large population in Asian countries including Japan, or HLA-A02:01 positive individuals and HLA-A02:06 positive individuals with a large population in Europe and the United States (Cao K et al., Hum Immunol 2001, 62(9): 1009-1030; Gonzalez-Galarza FF et al., Nucleic Acids Res 2020, 48(D1):D783-D788). Among the epitope peptides of the present invention, some have been demonstrated to be able to induce a specific and strong immune response against COVID-19 even in HLA-A24:02 positive individuals with a large population in Asian countries including Japan. * 24:02 positive individuals or HLA-A * 02:01 positive individuals and HLA-A * 02:06 positive individuals (Cao K et al., Hum Immunol 2001, 62(9): 1009-1030; Gonzalez-Galarza FF et al., Nucleic Acids Res 2020, 48(D1):D783-D788) as the target, it has been demonstrated that it can induce a specific and strong immune response against COVID-19. Among the epitope peptides of the present invention, some have been demonstrated to be able to induce a specific and strong immune response against COVID-19 even in HLA-A24:02 positive individuals with a large population in Asian countries including Japan. * It has been demonstrated that it can induce a specific and strong immune response against COVID-19 even in HLA-A24:02 positive individuals with a large population in Asian countries including Japan. Since the similarity between the amino acid sequence of the epitope peptide provided by the present invention and the amino acid sequence derived from human proteins is low, the creation of a highly safe vaccine that is unlikely to cause unexpected side reactions can be expected. On the other hand, since it is an amino acid sequence commonly observed in SARS-CoV and MERS-CoV that have prevailed in the past, it may also be similarly observed in novel coronavirus proteins that will appear in the future. Therefore, the vaccine composed of the epitope peptide can be effective not only against the current SARS-CoV-2 but also against future prevalent coronavirus infections. The present invention also provides a composition comprising one or more peptides of the present invention, one or more polynucleotides encoding one or more peptides of the present invention, the APC of the present invention, exosomes presenting the peptides of the present invention, and / or the CTL of the present invention. The composition of the present invention is preferably a pharmaceutical composition. The pharmaceutical composition of the present invention can be used for the treatment and / or prevention of coronavirus infection and for suppressing the progression to severe cases. It can also be used to induce an immune response against coronavirus infection. When administered to a subject, the peptide of the present invention is presented on the surface of an APC, thereby inducing CTL targeting the peptide. Accordingly, it is a further object of the present invention to provide a composition for inducing CTL, the composition comprising one or more peptides of the present invention, one or more polynucleotides encoding one or more peptides of the present invention, the APC of the present invention, and / or exosomes presenting the peptides of the present invention. It is a further object of the present invention to provide a method for inducing an APC having CTL-inducing ability, the method comprising the step of contacting an APC with one or more peptides of the present invention or the step of introducing into the APC a polynucleotide encoding any one of the peptides of the present invention. The present invention also provides a method for inducing CTL, the method comprising the step of co-culturing CD8-positive T cells with an APC presenting a complex of an HLA antigen and a peptide of the present invention on its own surface, the step of co-culturing CD8-positive T cells with exosomes presenting a complex of an HLA antigen and a peptide of the present invention on their own surfaces, or the step of introducing into CD8-positive T cells a vector comprising polynucleotides encoding each subunit of a T cell receptor (TCR) capable of binding to a peptide of the present invention presented by an HLA antigen on the cell surface. It is yet another object of the present invention to provide an isolated APC that presents a complex of an HLA antigen and the peptide of the present invention on its surface. The present invention further provides an isolated CTL that targets the peptide of the present invention. These APCs and CTLs can be used for immunotherapy against coronavirus infection. Another object of the present invention is to provide a method for inducing an immune response against coronavirus infection in a subject, the method comprising administering to the subject the peptide of the present invention, a polynucleotide encoding the peptide, the APC of the present invention, an exosome presenting the peptide of the present invention, and / or the CTL of the present invention. Further, another object of the present invention is to provide a method for treating and / or preventing coronavirus infection and suppressing its exacerbation in a subject, the method comprising administering to the subject the peptide of the present invention, a polynucleotide encoding the peptide, the APC of the present invention, an exosome presenting the peptide of the present invention, and / or the CTL of the present invention. The present invention also relates to a TCR expressed by a T cell that recognizes a peptide derived from a SARS-CoV-2 protein. The TCR is a protein molecule composed of a dimer of an α chain and a β chain. Human T cells recognize peptides presented on MHC class I (also known as HLA, Human Leukocyte Antigen) molecules through the TCR. As a result, induction of T cell proliferation, differentiation, cytokine production, or secretion of cytotoxic substances (perforin and granzyme) occurs. The TCRα gene includes a Vα gene, a Jα gene, and a Cα gene. The TCRβ gene includes a Vβ gene, a Dβ gene, a Jβ gene, and a Cβ gene. The region that determines the specificity of the TCR for a peptide is called the Complementarity Determining Region (CDR), and there are CDR1, CDR2, and CDR3. Among them, since CDR3 directly contacts the peptide, its amino acid sequence is very important for determining specificity. In the TCRα chain, the V-J interval corresponds to CDR3, and in the TCRβ chain, the V-D and D-J intervals correspond to CDR3, and diversity is generated by base insertion or deletion. SARS-CoV-2 infection or vaccination may selectively increase T cells that recognize SARS-CoV-2 protein-derived peptides. For the purpose of examining such an immune response in terms of changes in the detection frequency of specific TCRs in peripheral blood, the amino acid sequences of TCRs (especially the amino acid sequences in CDR3) identified from T cells that recognize peptides derived from the SARS-CoV-2 proteins shown herein are of very high utility value. That is, the present invention aims to provide a method for knowing the immune response of a subject to SARS-CoV-2, which includes a step of determining the detection frequency of TCRs in the peripheral blood of the subject. In addition to the above, other objects and features of the present invention will become more fully apparent by reading the following detailed description in conjunction with the accompanying charts and examples. However, it should be understood that both the foregoing summary of the invention and the following detailed description are exemplary aspects and do not limit the present invention or other alternative aspects of the present invention. In particular, although the present invention is described herein with reference to several specific aspects, it should be understood that the description is illustrative of the present invention and is not configured to limit the present invention. Without departing from the spirit and scope of the present invention as described by the appended claims, those skilled in the art can conceive of various changes and applications. Similarly, other objects, features, benefits, and advantages of the present invention will become apparent from the specific aspects described above and below and will be readily apparent to those skilled in the art. Such objects, features, benefits, and advantages will become apparent from the above in conjunction with the appended examples, data, charts, and any reasonable inferences drawn therefrom, either alone or in consideration of the references incorporated herein. Figure 1 consists of an image showing the results of an IFN-γ enzyme-linked immunospot (ELISPOT) assay performed using cells induced with peptides derived from SARS-CoV-2 proteins. In the figure, "(+)" indicates HLA-A pulsed with the peptide of interest. *02:01 shows IFN-γ production against the expression target cells (T2 cells), where "(-)" indicates IFN-γ production against T2 cells not pulsed with any peptide (negative control). It can be seen from the comparison with the negative control that peptide-specific IFN-γ production was observed in Peptide 1 (SEQ ID NO: 1), Peptide 2 (SEQ ID NO: 2), Peptide 3 (SEQ ID NO: 3), Peptide 4 (SEQ ID NO: 4), Peptide 5 (SEQ ID NO: 5), Peptide 7 (SEQ ID NO: 7), Peptide 9 (SEQ ID NO: 9), Peptide 10 (SEQ ID NO: 10), Peptide 11 (SEQ ID NO: 11), Peptide 12 (SEQ ID NO: 12), Peptide 13 (SEQ ID NO: 13), Peptide 14 (SEQ ID NO: 14), and Peptide 15 (SEQ ID NO: 15) (Figure 1a). On the other hand, Peptide 8 (SEQ ID NO: 8) is shown as an example of typical negative data where no peptide-specific IFN-γ production was observed (Figure 1b). Figure 2 consists of a line graph representing the results of measuring IFN-γ produced from cells stimulated with Peptide 2 (SEQ ID NO: 2), Peptide 3 (SEQ ID NO: 3), Peptide 4 (SEQ ID NO: 4), Peptide 7 (SEQ ID NO: 7), Peptide 10 (SEQ ID NO: 10), Peptide 11 (SEQ ID NO: 11), Peptide 12 (SEQ ID NO: 12), or Peptide 15 (SEQ ID NO: 15) by enzyme-linked immunosorbent assay (ELISA). These results show that HLA-A * 02:01-restricted CTL lines were established. In the figure, "(+)" indicates HLA-A pulsed with the peptide of interest * 02:01 shows IFN-γ production of the CTL line against the expression target cells (T2 cells), and "(-)" indicates IFN-γ production of the CTL line against T2 cells not pulsed with any peptide. The R / S ratio represents the ratio of the number of cells in the CTL line, which are the responder cells, to the number of cells in the target cells that stimulate it, the stimulator cells. Figure 3 consists of images showing the results of an IFN-γ enzyme-linked immunosorbent spot (ELISPOT) assay performed using cells induced with peptides derived from the SARS-CoV-2 protein. In the figure, “(+)” indicates IFN-γ production against HLA-A * 24:02-expressing target cells (TISI cells) pulsed with the peptide of interest, and “(−)” indicates IFN-γ production against TISI cells not pulsed with any peptide (negative control). It can be seen from the comparison with the negative control that peptide-specific IFN-γ production was observed in peptide 3 (SEQ ID NO: 3) and peptide 11 (SEQ ID NO: 11) (Figure 3a). On the other hand, peptide 4 (SEQ ID NO: 4) is shown as an example of typical negative data where no peptide-specific IFN-γ production was observed (Figure 3b). Figure 4 consists of a line graph representing the results of measuring IFN-γ produced from cells stimulated with peptide 3 (SEQ ID NO: 3) or peptide 11 (SEQ ID NO: 11) by enzyme-linked immunosorbent assay (ELISA). These results indicate that HLA-A * 24:02-restricted CTL lines that produce IFN-γ specifically to the peptide were established after induction with the peptide. In the figure, “(+)” indicates IFN-γ production of the CTL line against HLA-A * 24:02-expressing target cells (TISI cells) pulsed with the peptide of interest, and “(−)” indicates IFN-γ production of the CTL line against TISI cells not pulsed with any peptide. The R / S ratio represents the ratio of the number of cells in the CTL line, which are responder cells, to the number of cells in the target cells that stimulate it, the stimulator cells. Figure 5 consists of images showing the results of an IFN-γ enzyme-linked immunosorbent spot (ELISPOT) assay performed using cells induced with peptides derived from the SARS-CoV-2 protein. In the figure, “(+)” indicates IFN-γ production against HLA-A *02:06 shows the IFN-γ production against the expression target cells (HEV0011 cells), where "(-)" indicates the IFN-γ production against HEV0011 cells without pulsing with any peptide (negative control). It can be seen from the comparison with the negative control that peptide-specific IFN-γ production was observed in peptide 3 (SEQ ID NO: 3), peptide 4 (SEQ ID NO: 4), peptide 7 (SEQ ID NO: 7), peptide 10 (SEQ ID NO: 10), peptide 11 (SEQ ID NO: 11), peptide 12 (SEQ ID NO: 12), and peptide 15 (SEQ ID NO: 15) (Figure 5a). On the other hand, as an example of typical negative data where peptide-specific IFN-γ production was not observed, peptide 2 (SEQ ID NO: 2) is shown (Figure 5b). Figure 6 consists of a line graph representing the results of measuring IFN-γ produced from cells stimulated with peptide 3 (SEQ ID NO: 3), peptide 4 (SEQ ID NO: 4), peptide 7 (SEQ ID NO: 7), peptide 10 (SEQ ID NO: 10), peptide 11 (SEQ ID NO: 11), peptide 12 (SEQ ID NO: 12), or peptide 15 (SEQ ID NO: 15) by enzyme-linked immunosorbent assay (ELISA). These results show that HLA-A that produces IFN-γ specifically in response to the peptide after induction by the peptide * 02:06 shows the establishment of HLA-A restricted CTL lines. In the figure, "(+)" indicates HLA-A pulsed with the peptide of interest * 02:06 shows the IFN-γ production of the CTL line against the expression target cells (HEV0011 cells), where "(-)" indicates the IFN-γ production of the CTL line against HEV0011 cells without pulsing with any peptide. The R / S ratio represents the ratio of the number of cells in the CTL line, which are responder cells, to the number of cells in the target cells that stimulate it, the stimulator cells. Figure 7 consists of a line graph showing IFN-γ production of SARS-CoV-2 protein-derived peptide-specific CTL clones established by limiting dilution from PBMC after in vitro CTL induction. IFN-γ production of CTL clones against target cells (+) pulsed with SARS-CoV-2 protein-derived peptides was observed, while no significant IFN-γ production of CTL clones against target cells (-) not pulsed with peptides was observed. From this, it was confirmed that the CTL clones recognized peptides derived from SARS-CoV-2 proteins presented by HLA. The R / S ratio represents the ratio of the number of cells of CTL clones, which are responder cells, to the number of target cells, which stimulate them. Figure 8 consists of the results of a tetramer assay performed on PBMC collected from SARS-CoV-2 non-infected individuals. A tetramer-positive CD8-positive T cell population that recognizes a SARS-CoV-2 protein-derived peptide presented on HLA-A*02:01 was detected from PBMC derived from SARS-CoV-2 non-infected individuals. In practicing or testing aspects of the present invention, any methods and materials similar or equivalent to those described herein can be used, but the preferred methods, devices, and materials are described herein. However, prior to describing the materials and methods of the present invention, it should be understood that the specific sizes, shapes, dimensions, materials, methodologies, protocols, etc. described herein are subject to change according to conventional experimental methods and optimizations, and thus the present invention is not limited thereto. It should also be understood that the terminology used in this description is for the purpose of describing only specific types or aspects and is not intended to limit the scope of the present invention, which is limited only by the appended claims. I. Definitions As used herein, the words "a," "an," and "the" mean "at least one" unless otherwise specified. The terms "isolated" and "purified" as used with respect to a substance (e.g., a peptide, antibody, polynucleotide, etc.) indicate that the substance is substantially free of at least one substance that would otherwise be present in its natural source. Thus, an isolated or purified peptide refers to a peptide that is substantially free of other cellular materials, such as carbohydrates, lipids, and other contaminating proteins, from the cell or tissue source from which the peptide is derived. When the peptide is chemically synthesized, an isolated or purified peptide refers to a peptide that is substantially free of precursor substances or other chemical substances. The term "substantially free of cellular materials" includes preparations of peptides that have been separated from the cellular components of isolated or recombinantly produced cells. Thus, a peptide substantially free of cellular materials encompasses preparations of peptides that contain less than about 30%, 20%, 10%, or 5%, 3%, 2% or 1% (dry weight basis) of other cellular materials. When a peptide is recombinantly produced, an isolated or purified peptide is substantially free of the culture medium, and a peptide substantially free of the culture medium encompasses preparations of peptides that contain the culture medium at less than about 20%, 10%, or 5%, 3%, 2% or 1% (dry weight basis) of the volume of the peptide preparation. When a peptide is chemically synthesized, an isolated or purified peptide is substantially free of precursor substances and other chemical substances, and a peptide substantially free of precursor substances and other chemical substances encompasses preparations of peptides that contain precursor substances and other chemical substances at less than about 30%, 20%, 10%, 5%, 3%, 2% or 1% (dry weight basis) of the volume of the peptide preparation. That a particular peptide preparation is an isolated or purified peptide can be confirmed, for example, by the appearance of a single band after techniques such as sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis and Coomassie Brilliant Blue staining of the gel. In a preferred embodiment, the peptides and polynucleotides of the invention are isolated or purified. The terms "polypeptide", "peptide", "protein" and "protein" are used interchangeably herein and refer to polymers of amino acid residues. The term applies to both natural amino acid polymers and unnatural amino acid polymers containing one or more unnatural amino acid residues. Unnatural amino acids include amino acid analogs and amino acid mimetics. As used herein, the term "amino acid" refers to natural amino acids, as well as amino acid analogs and amino acid mimetics that function in a manner similar to natural amino acids. Natural amino acids are those encoded by the genetic code and those that are modified after translation within cells (e.g., hydroxyproline, γ-carboxyglutamic acid, and O-phosphoserine, etc.). The phrase "amino acid analog" refers to a compound having the same basic chemical structure as a natural amino acid (a hydrogen, carboxy group, amino group, and an α-carbon bonded to an R group), but having a modified R group or a modified backbone (e.g., homoserine, norleucine, methionine sulfoxide, and methionine methyl sulfonium, etc.). The phrase "amino acid mimetic" refers to a compound having a structure different from that of a general amino acid but having a similar function. The amino acid may be either an L-amino acid or a D-amino acid, but the peptides of the present invention are preferably polymers of L-amino acids. The terms "polynucleotide", "oligonucleotide", and "nucleic acid" are used interchangeably herein and refer to polymers of nucleotides. As used herein, the term "composition" is intended to encompass a product containing a specific amount of a specific component, and any product directly or indirectly resulting from a combination of specific amounts of specific components. When the composition is a pharmaceutical composition, the term "composition" is intended to encompass a product containing an active ingredient and an inert ingredient, as well as any product directly or indirectly resulting from a combination, complex formation, or aggregation of any two or more components, from the dissociation of one or more components, or from other types of reactions or interactions of one or more components. Accordingly, the pharmaceutical compositions of the present invention encompass any compositions prepared by mixing a compound or cell of the present invention with a pharmaceutically or physiologically acceptable carrier. As used herein, the phrases "pharmaceutically acceptable carrier" or "physiologically acceptable carrier" mean a pharmaceutically or physiologically acceptable material, composition, substance, or medium, including but not limited to liquid or solid bulking agents, diluents, excipients, solvents, and encapsulating materials. Unless otherwise specified, the term "viral infection" refers to a coronavirus infection, and examples of coronaviruses include, but are not limited to, SARS-CoV-2, MERS-CoV, and SARS-CoV. Also, in an exemplary embodiment, "coronavirus infection" is a SARS-CoV-2 infection in an HLA-A24 or HLA-A02 positive subject. Unless otherwise specified, the terms "cytotoxic T lymphocyte", "cytotoxic T cell", and "CTL" are used interchangeably herein and, unless otherwise specified, refer to a subset of T lymphocytes that can recognize non-self cells (e.g., tumor / cancer cells, virus-infected cells) and induce the death of such cells. Unless otherwise specified, the term "HLA-A24" refers to HLA-A * 24:01, HLA-A * 24:02, HLA-A * 24:03, HLA-A * 24:04, HLA-A * 24:07, HLA-A * 24:08, HLA-A *24:20, HLA-A * 24:25, HLA-A * 24:88, etc., refers to HLA-A24 type including subtypes such as these. Unless otherwise specified, the term "HLA-A02 (or HLA-A2)" refers to HLA-A * 02:01, HLA-A * 02:02, A * 02:03, A * 02:04, A * 02:05, A * 02:06, A * 02:07, A * 02:10, A * 02:11, A * 02:13, A * 02:16, A * 02:18, A * 02:19, A * 02:28, and A * 02:50, etc., refers to HLA-A02 type including subtypes such as these. Unless otherwise specified, the term "coronavirus protein" refers to a protein consisting of the full-length amino acid sequence of each protein encoded by the genomic sequence of the coronavirus. Preferred examples include the structural proteins and non-structural proteins of SARS-CoV-2. Examples of coronaviruses include, but are not limited to, SARS-CoV-2, MERS-CoV, and SARS-CoV. The genomic base sequences (reference sequences) of each of these coronaviruses and the amino acid sequences of the coronavirus proteins encoded thereby can be obtained, for example, with the following Genbank accession numbers: SARS-CoV-2: MN908947 MERS-CoV: JX869059 SARS-CoV: Tor2: AY274119, BJ01: AY278488 or GZ02: AY390556 Unless otherwise specified, the term "SARS-CoV-2 protein" refers to a protein consisting of the full-length amino acid sequence of each protein encoded by the genomic sequence of SARS-CoV-2, including the four structural proteins and six non-structural proteins of SARS-CoV-2. The four structural proteins and six non-structural proteins are summarized in Table 1. In the table, for the non-structural protein orf1ab, due to ribosomal frameshift, two ORFs of 266..13468 and 13468..21555 in the reference sequence are connected to form one ORF. Unless otherwise specified, the terms "coronavirus-infected cell", "virus-infected cell" and "infected cell" are used interchangeably herein and refer to a cell infected with a coronavirus, unless otherwise specified. Examples of coronaviruses include, but are not limited to, SARS-CoV-2, MERS-CoV and SARS-CoV. As used herein, the term "infection" includes virus entry and / or virus proliferation in a cell or body tissue, and the pathological conditions resulting from virus entry and virus proliferation. The entry and proliferation stages of the virus life cycle include, but are not limited to, the virus particle binding to the cell, introducing the virus genetic information into the cell, expressing virus proteins, producing new virus particles, and releasing virus particles from the cell. In the context of a subject or patient, the expression "the HLA antigen of the subject (or patient) is HLA-A24 or HLA-A02" as used herein means that the subject or patient homozygously or heterozygously possesses the HLA-A24 or HLA-A02 antigen gene as an MHC (major histocompatibility complex) class I molecule, and the HLA-A24 or HLA-A02 antigen is expressed as an HLA antigen in the cells of the subject or patient. As long as the methods and compositions of the present invention are useful in the context of "treatment" of coronavirus infections, a treatment is considered "effective" when the treatment results in clinical benefits, such as alleviation of clinical symptoms of coronavirus infection in a subject, suppression of disease progression, etc. The main symptoms of coronavirus infection are generally known to include fever, cough, chills, stiffness, and muscle pain, etc. The symptoms of many infected patients are mild and are said to recover within about 1-2 weeks. However, in some patients, symptoms of respiratory distress are observed, and may be accompanied by significant dyspnea, hypoxemia, and even acute respiratory distress syndrome (ARDS). Also, according to recent reports, particularly in patients infected with SARS-CoV-2, specific symptoms such as anosmia and dysgeusia have been observed in relatively mild patients. Alternatively, it is also known that thrombosis and cytokine storms in severely ill patients lead to disease progression. When the treatment is applied prophylactically, "effective" means that the treatment delays or prevents the onset of coronavirus infection, or prevents or alleviates the clinical symptoms of coronavirus infection. Efficacy is determined in relation to any known method for diagnosing or treating coronavirus infection. For example, if any of the specific symptoms listed above are suppressed, it can be said that the efficacy of the treatment or prevention is demonstrated. As long as the methods and compositions of the present invention are useful in the context of "prevention" of coronavirus infections, the term "prevention" as used herein includes any action that reduces the burden of mortality or morbidity due to the disease. Prevention can be carried out at the "primary, secondary, and tertiary prevention levels". Primary prevention aims to avoid the occurrence of the disease, while secondary and tertiary level prevention includes actions aimed at reducing the adverse effects of existing diseases by preventing the progression of the disease and the appearance of symptoms, as well as restoring function and reducing disease-related complications. Alternatively, prevention can include a wide range of prophylactic treatments aimed at alleviating the severity of a particular disorder, such as reducing clinical symptoms such as fever, shortness of breath, cough, upper respiratory tract infection, etc. In the context of the present invention, the treatment and / or prevention of coronavirus infection and / or the suppression of its exacerbation include the delay in the onset of at least one symptom of coronavirus infection or the improvement thereof. It also includes the inhibition of virus growth in coronavirus-infected cells, etc. Effective treatment and / or prevention of coronavirus infection reduce the mortality rate, improve the prognosis of individuals infected with coronavirus infection, and alleviate the symptoms associated with coronavirus infection. For example, the alleviation or improvement of symptoms constitutes effective treatment and / or prevention, including a reduction of 10%, 20%, 30% or more, or a stable state of symptoms. In the present invention, the inhibition of virus growth includes the inhibition of the virus replication process in infected cells. The CTL induced by the peptide of the present invention, in virus-infected cells, when each virus protein expressed in the virus replication process is antigen-presented, damages the cell functions (gene replication and protein translation) of the infected cells by its cytotoxic activity. Alternatively, CTL destroys the infected cells themselves. As a result, the replication process of virus particles that depends on the cell functions of the infected cells is inhibited, and the growth of the virus is inhibited. In the present invention, the suppression of exacerbation means the suppression of the worsening or progression of any symptom associated with coronavirus infection. Specifically, the progression of the respiratory distress symptoms that require invasive treatment such as oxygen inhalation or the attachment of a ventilator or an extracorporeal membrane oxygenation (ECMO) is a typical example of exacerbation in coronavirus infection. Therefore, the prevention, prophylaxis, or alleviation of the progression (worsening) of these symptoms is included in the suppression of exacerbation in the present invention. In the context of the present invention, the term "antibody" refers to immunoglobulins and fragments thereof that specifically react with a designated protein or its peptide. Antibodies can include human antibodies, primatized antibodies, chimeric antibodies, bispecific antibodies, humanized antibodies, antibodies fused with other proteins or radiolabels, and antibody fragments. Further, the term "antibody" is used herein in a broad sense and specifically includes intact monoclonal antibodies, polyclonal antibodies, multispecific antibodies (e.g., bispecific antibodies) formed from two or more intact antibodies, and also antibody fragments as long as they exhibit the desired biological activity. The "antibody" may be an antibody of any class (e.g., IgA, IgD, IgE, IgG, and IgM). The present invention relates to a TCR expressed by T cells that recognize a SARS-CoV-2-derived peptide. The TCR is a protein molecule composed of a dimer of an α chain and a β chain. Human T cells recognize peptides presented on MHC class I (also known as HLA, Human Leukocyte Antigen) molecules through the TCR. As a result, induction of T cell proliferation, differentiation, cytokine production, or secretion of cytotoxic substances (perforin and granzyme) etc. is induced. The TCR-α gene includes the Vα gene, Jα gene, and Cα gene. The TCR-β gene includes the Vβ gene, Dβ gene, Jβ gene, and Cβ gene. The region that determines the specificity of the TCR for a peptide is called the Complementarity Determining Region (CDR), and CDR1, CDR2, and CDR3 exist. Among them, since CDR3 directly contacts the peptide, its amino acid sequence is very important in determining the antigen recognition specificity of the TCR. In the TCR-α chain, the region between V and J corresponds to CDR3, and in the TCR-β chain, the regions between V and D and between D and J correspond to CDR3, and diversity is generated by base insertions and deletions. In the present invention, the TCR refers to a protein molecule that is expressed in T cells and consists of a dimer of an α chain and a β chain. In the present invention, the T cells are human T cells, and may be human T cells that recognize a SARS-CoV-2-derived peptide. In the present invention, TCR is expressed on T cells and, through itself, recognizes a peptide presented on MHC class I (also known as HLA, Human Leukocyte Antigen) molecules, and refers to a molecule that induces actions such as proliferation, differentiation, cytokine production, or secretion of cytotoxic substances (perforin and granzyme) of T cells. The TCR-α gene includes the Vα gene, Jα gene, and Cα gene. The TCR-β gene includes the Vβ gene, Dβ gene, Jβ gene, and Cβ gene. The region that determines the specificity of TCR for a peptide is called the Complementarity Determining Region (CDR), and CDR1, CDR2, and CDR3 exist. Among them, since CDR3 directly contacts the peptide, its amino acid sequence is very important in determining the antigen recognition specificity of TCR. In the TCR-α chain, the region between V and J, and in the TCR-β chain, the regions between V and D and between D and J correspond to CDR3, and diversity is generated by insertion or deletion of bases. In the present invention, TCR may have a CDR sequence that is expressed on T cells and specifically recognizes a SARS-CoV-2-derived peptide. In the present invention, "history of coronavirus infection" refers to the fact that the subject has been infected with a coronavirus, particularly SARS-CoV-2, in the past. Even if the subject was asymptomatic during the past infection, the past infection can be confirmed by detecting the TCR of the present invention. In addition, a subject in the current infected state means that the infection was established before. Therefore, a subject in the current infected state has a history of coronavirus infection in the past. COVID-19 means "novel coronavirus infection" confirmed by a doctor's diagnosis. Unless otherwise specified, all technical terms and scientific terms used in this specification have the same meaning as those commonly understood by those skilled in the technical field to which the present invention belongs. II. Peptide HLA-A24 is an allele frequently found in Asians, and HLA-A02 is an allele frequently found in Caucasians (Sette A, Sidney J., Immunogenetics 1999, 50:201-12; Cao K et al., Hum Immunol 2001, 62(9):1009-1030; Gonzalez-Galarza FF et al., Nucleic Acids Res 2020, 48(D1):D783-D788). Therefore, by providing CTL-inducing peptides derived from SARS-CoV-2 proteins restricted by HLA-A24 or HLA-A02, an effective treatment method for coronavirus infection can be provided to many Asians or Caucasians. Thus, the present invention provides peptides derived from SARS-CoV-2 proteins that can induce CTLs in an HLA-A24- or HLA-A02-restricted manner. The peptide of the present invention is a peptide derived from a SARS-CoV-2 protein that can induce CTLs in an HLA-A24- or HLA-A02-restricted manner. Examples of peptides that can induce CTLs in an HLA-A02-restricted manner include peptides having an amino acid sequence selected from SEQ ID NOs: 1, 2, 3, 4, 5, 7, 9, 10, 11, 12, 13, 14, and 15. Examples of peptides that can induce CTLs in an HLA-A24-restricted manner include peptides having an amino acid sequence selected from SEQ ID NOs: 3 and 11. By in vitro stimulation of T cells with dendritic cells pulsed with these peptides, CTLs having cytotoxic activity specific to these peptides can be established. The established CTLs exhibit specific cytotoxic activity against target cells pulsed with each peptide. CTL is induced by receiving the presentation of a coronavirus antigen (epitope peptide derived from a coronavirus protein), and then recognizes the epitope peptide presented on the human leukocyte antigen (HLA) class I molecule expressed on the surface of coronavirus-infected cells, and kills the virus-infected cells. Therefore, the coronavirus antigen is an excellent target for immunotherapy. Thus, the peptide of the present invention can be suitably used for the immunotherapy of coronavirus infection. Preferred peptides are nonapeptides (peptides consisting of 9 amino acid residues) or decapeptides (peptides consisting of 10 amino acid residues), and peptides consisting of amino acid sequences selected from SEQ ID NOs: 1, 2, 3, 4, 5, 7, 9, 10, 11, 12, 13, 14 and 15 are more preferred. For example, a peptide having the amino acid sequence set forth in SEQ ID NO: 1, 2, 3, 4, 5, 7, 9, 10, 11, 12, 13, 14 or 15 is suitable for inducing CTLs that exhibit specific cytotoxic activity against coronavirus-infected cells having HLA-A02, and can be suitably used for the immunotherapy of coronavirus infection in HLA-A02 positive patients. Also, for example, a peptide having the amino acid sequence set forth in SEQ ID NO: 3 or 11 is suitable for inducing CTLs that exhibit specific cytotoxic activity against coronavirus-infected cells having HLA-A24, and can be suitably used for the immunotherapy of coronavirus infection in HLA-A24 positive patients. In a more preferred embodiment, the peptide of the present invention is a peptide consisting of an amino acid sequence selected from SEQ ID NOs: 1, 2, 3, 4, 5, 7, 9, 10, 11, 12, 13, 14 and 15 for HLA-A02 positive patients, and a peptide consisting of an amino acid sequence selected from SEQ ID NOs: 3 and 11 for HLA-A24 positive patients. The peptide of the present invention can have additional amino acid residues adjacent to the amino acid sequence of the peptide of the present invention as long as the resulting peptide retains the CTL-inducing ability of the original peptide. The additional amino acid residues can be composed of any type of amino acid as long as they do not impair the CTL-inducing ability of the original peptide. Thus, the peptide of the present invention includes peptides having CTL-inducing ability, including an amino acid sequence selected from SEQ ID NOs: 1, 2, 3, 4, 5, 7, 9, 10, 11, 12, 13, 14, and 15. Such peptides are, for example, less than about 40 amino acids in length, often less than about 20 amino acids in length, and usually less than about 15 amino acids in length. Thus, the peptide of the present invention includes peptides 10 amino acids in length or 11 to 40 amino acids in length that are generated by adjoining additional amino acids to the peptide if the original peptide is a nonapeptide. Also, if the original peptide is a decapeptide, it includes peptides 11 to 40 amino acids in length. Such peptides can be, for example, peptides 11 to 20 amino acids in length, and can be peptides 11 to 15 amino acids in length. Preferred examples of the additional amino acid residues are amino acid residues adjacent to the amino acid sequence of the peptide of the present invention in the full-length amino acid sequence of each protein encoded by the genomic sequence of SARS-CoV-2 (for example, SEQ ID NOs: 17-26). Thus, the peptide of the present invention includes peptide fragments of SARS-CoV-2 proteins, including an amino acid sequence selected from SEQ ID NOs: 1, 2, 3, 4, 5, 7, 9, 10, 11, 12, 13, 14, and 15, which have CTL-inducing ability. Generally, modification of one, two, or more amino acids in a peptide does not affect the function of the peptide and in some cases may even enhance the desired function of the original peptide. In fact, modified peptides (i.e., peptides composed of amino acid sequences in which one, two, or several amino acid residues have been modified (i.e., substituted, deleted, inserted, and / or added) compared to the original reference sequence) are known to retain the biological activity of the original peptide (Mark et al., Proc Natl Acad Sci USA 1984, 81: 5662-6; Zoller and Smith, Nucleic Acids Res 1982, 10: 6487-500; Dalbadie-McFarland et al., Proc Natl Acad Sci USA 1982, 79: 6409-13). Thus, in one aspect, the peptide of the present invention can be a peptide comprising an amino acid sequence in which one, two, or several amino acids are substituted, deleted, inserted, and / or added with respect to the amino acid sequence selected from SEQ ID NOs: 1, 2, 3, 4, 5, 7, 9, 10, 11, 12, 13, 14, and 15 and having CTL-inducing ability. One of ordinary skill in the art can recognize individual substitutions to an amino acid sequence that tend to result in conservation of the properties of the original amino acid side chain. Thus, they are often referred to as "conservative substitutions" or "conservative modifications," and modification of a protein by "conservative substitution" or "conservative modification" can result in a modified protein having a function similar to that of the original protein. Tables of conservative substitutions presenting amino acids that are functionally similar are well known in the art. Examples of the properties of functionally similar amino acid side chains include, for example, hydrophobic amino acids (A, I, L, M, F, P, W, Y, V), hydrophilic amino acids (R, D, N, C, E, Q, G, H, K, S, T), and side chains that commonly have the following functional groups or characteristics: aliphatic side chains (G, A, V, L, I, P); hydroxyl group-containing side chains (S, T, Y); sulfur atom-containing side chains (C, M); carboxylic acid and amide-containing side chains (D, N, E, Q); base-containing side chains (R, K, H); and aromatic-containing side chains (H, F, Y, W). In addition, the following 8 groups each contain amino acids that are recognized in the art as being conservative substitutions for each other: 1) Alanine (A), Glycine (G); 2) Aspartic acid (D), Glutamic acid (E); 3) Asparagine (N), Glutamine (Q); 4) Arginine (R), Lysine (K); 5) Isoleucine (I), Leucine (L), Methionine (M), Valine (V); 6) Phenylalanine (F), Tyrosine (Y), Tryptophan (W); 7) Serine (S), Threonine (T); and 8) Cysteine (C), Methionine (M) (see, e.g., Creighton, Proteins 1984). Such conservative modified peptides are also included in the peptides of the present invention. However, the peptides of the present invention are not limited thereto and may include non-conservative modifications as long as the modified peptides retain the CTL-inducing ability of the original peptides. Furthermore, the modified peptides do not exclude CTL-inducible peptides derived from polymorphic variants, interspecies homologs, and alleles of SARS-CoV-2 proteins. As long as the CTL-inducing ability of the original peptide is retained, a small number (e.g., 1, 2, or several) or a small proportion of amino acids can be modified (i.e., substituted, deleted, inserted, and / or added). As used herein, the term "several" means 5 or fewer amino acids, such as 4 or 3 or fewer. The proportion of amino acids to be modified is preferably 20% or less, more preferably 15% or less, even more preferably 10% or less, or 1-5%. When used in the context of immunotherapy, the peptides of the present invention should preferably be presented on the surface of cells or exosomes as a complex with HLA antigens. Therefore, the peptides of the present invention preferably have a high binding affinity for HLA antigens. Thus, the peptides may be modified by substitution, deletion, insertion, and / or addition of amino acid residues to obtain modified peptides with improved binding affinity. Since the regularity of the peptide sequences presented by binding to HLA antigens is known (Falk, et al., Immunogenetics 1994 40 232-41; Chujoh, et al., Tissue Antigens 1998: 52: 501-9; Takiguchi, et al., Tissue Antigens 2000: 55: 296-302.), modifications based on such regularity can be introduced into the peptides of the present invention. For example, in the case of a peptide having binding affinity for HLA Class I, generally, the second amino acid from the N-terminus and the C-terminal amino acid are often anchor residues involved in binding to HLA Class I (Rammensee HG, et al., Immunogenetics. 1995;41(4):178-228.). For example, peptides having high HLA-A02 binding affinity tend to have the second amino acid from the N-terminus substituted with leucine or methionine and / or the C-terminal amino acid substituted with valine or leucine. Therefore, in order to enhance the HLA-A02 binding affinity, it may be desirable to substitute the second amino acid from the N-terminus with leucine or methionine and / or substitute the C-terminal amino acid with valine or leucine. Therefore, peptides having an amino acid sequence selected from among SEQ ID NOs: 1, 2, 3, 4, 5, 7, 9, 10, 11, 12, 13, 14, and 15, wherein the second amino acid from the N-terminus is substituted with leucine or methionine and / or the C-terminus is substituted with valine or leucine, are encompassed by the present invention. Similarly, the present invention encompasses peptides comprising an amino acid sequence in which one, two, or several amino acids in SEQ ID NOs: 1, 2, 3, 4, 5, 7, 9, 10, 11, 12, 13, 14, and 15 have been substituted, deleted, inserted, and / or added, and which have one or both of the following characteristics: (a) the second amino acid from the N-terminus is leucine or methionine, and (b) the C-terminal amino acid is valine or leucine. In a preferred embodiment, the peptide of the present invention comprises an amino acid sequence in SEQ ID NOs: 1, 2, 3, 4, 5, 7, 9, 10, 11, 12, 13, 14, and 15 that includes either, or both, substitution of the second amino acid from the N-terminus with leucine or methionine and substitution of the C-terminal amino acid with valine or leucine. For example, among peptides having a high HLA-A02 binding affinity, peptides having a high binding affinity for HLA-A*02:06 tend to have the second amino acid from the N-terminus substituted with valine or glutamine and / or the C-terminal amino acid substituted with valine or leucine. Therefore, in order to enhance the HLA-A*02:06 binding affinity, it may be desirable to substitute the second amino acid from the N-terminus with valine or glutamine and / or substitute the C-terminal amino acid with valine or leucine. Therefore, peptides having an amino acid sequence selected from among SEQ ID NOs: 3, 4, 7, 10, 11, 12, and 15, in which the second amino acid from the N-terminus is substituted with valine or glutamine and / or the C-terminus is substituted with valine or leucine, are encompassed by the present invention (Table 1 of WO2010 / 047310). Similarly, the present invention encompasses peptides comprising an amino acid sequence in which one, two, or several amino acids in SEQ ID NOs: 3, 4, 7, 10, 11, 12, and 15 are substituted, deleted, inserted, and / or added, and which have one or both of the characteristics that (a) the second amino acid from the N-terminus is valine or glutamine, and (b) the C-terminal amino acid is valine or leucine. In a preferred embodiment, the peptide of the present invention comprises an amino acid sequence in which either, or both, of the substitution of the second amino acid from the N-terminus with valine or glutamine and the substitution of the C-terminal amino acid with valine or leucine in the amino acid sequences of SEQ ID NOs: 3, 4, 7, 10, 11, 12, and 15 are included. For example, peptides having high HLA-A24 binding affinity tend to have the second amino acid from the N-terminus substituted with phenylalanine, tyrosine, methionine, or tryptophan. Similarly, peptides with the C-terminal amino acid substituted with phenylalanine, leucine, isoleucine, tryptophan, or methionine also tend to have high HLA-A24 binding affinity. Therefore, in order to enhance the HLA-A24 binding affinity, it may be desirable to substitute the second amino acid from the N-terminus with phenylalanine, tyrosine, methionine, or tryptophan, and / or substitute the C-terminal amino acid with phenylalanine, leucine, isoleucine, tryptophan, or methionine. Therefore, peptides having an amino acid sequence selected from SEQ ID NOs: 3 and 11, wherein the second amino acid from the N-terminus is substituted with phenylalanine, tyrosine, methionine, or tryptophan, and / or the C-terminus is substituted with phenylalanine, leucine, isoleucine, tryptophan, or methionine, are encompassed by the present invention. Similarly, the present invention encompasses peptides comprising an amino acid sequence in which one, two, or several amino acids are substituted, deleted, inserted, and / or added in SEQ ID NOs: 3 and 11, and having one or both of the following characteristics: (a) the second amino acid from the N-terminus is phenylalanine, tyrosine, methionine, or tryptophan; and (b) the C-terminal amino acid is phenylalanine, leucine, isoleucine, tryptophan, or methionine. In a preferred embodiment, the peptides of the present invention comprise an amino acid sequence including either or both of the substitution of the second amino acid from the N-terminus with phenylalanine, tyrosine, methionine, or tryptophan and the substitution of the C-terminal amino acid with phenylalanine, leucine, isoleucine, tryptophan, or methionine in the amino acid sequences of SEQ ID NOs: 3 and 11. Substitutions can be introduced not only at the terminal amino acids but also at potential T cell receptor (TCR) recognition sites of the peptide. Some studies, for example, CAP1, p53 （264-272）, Her-2 / neu （369-377） , or gp100 （209-217） It has been demonstrated that peptides having amino acid substitutions such as these can have activity equivalent to or superior to that of the original peptide (Zaremba et al. Cancer Res. 57, 4570-4577, 1997; T. K. Hoffmann et al. J Immunol. (2002) Feb 1;168(3):1338-47; S. O. Dionne et al. Cancer Immunol immunother. (2003) 52: 199-206; and S. O. Dionne et al. Cancer Immunology, Immunotherapy (2004) 53, 307-14). The present invention also contemplates that one, two, or several amino acids can be added to the N-terminus and / or C-terminus of the peptides of the present invention (for example, peptides consisting of amino acid sequences selected from SEQ ID NOs: 1, 2, 3, 4, 5, 7, 9, 10, 11, 12, 13, 14, and 15). Such modified peptides that retain CTL-inducing ability are also included in the present invention. For example, a peptide having one, two, or several amino acids added to the N-terminus and / or C-terminus of a peptide consisting of the amino acid sequence set forth in SEQ ID NO: 1, 2, 3, 4, 5, 7, 9, 10, 11, 12, 13, 14, or 15, when contacted with an APC, is taken up into the APC and undergoes processing to become a peptide consisting of the amino acid sequence set forth in SEQ ID NO: 1, 2, 3, 4, 5, 7, 9, 10, 11, 12, 13, 14, or 15. Thereafter, it can be presented on the cell surface of the APC via the antigen presentation pathway, thereby inducing CTL. However, when the amino acid sequence of a peptide is identical to a part of the amino acid sequence of an endogenous or exogenous protein having different functions, side effects such as autoimmune disorders and / or allergic symptoms to specific substances may be induced. Therefore, in order to avoid the situation where the amino acid sequence of the peptide matches the amino acid sequence of other proteins, it is preferable to perform a homology search using an available database. If it is revealed from the homology search that there is not even a peptide with one or two amino acids different from the target peptide, the target peptide can be modified in order to increase its binding affinity to HLA antigen and / or increase its CTL-inducing ability without the risk of such side effects. Peptides in which one, two, or several amino acids of the peptide of the present invention are modified are predicted to be able to retain the CTL-inducing ability of the original peptide, but it is preferable to confirm the CTL-inducing ability for the modified peptides. As used herein, the term "peptide having CTL-inducing ability" refers to a peptide in which CTL is induced by APC stimulated with the peptide. "Induction of CTL" includes induction of differentiation into CTL, induction of CTL activation, induction of CTL proliferation, induction of cytotoxic activity of CTL, induction of lysis of target cells by CTL, and induction of increased IFN-γ production by CTL. Confirmation of CTL-inducing ability can be performed by inducing APCs (e.g., B lymphocytes, macrophages, and dendritic cells) carrying HLA antigens, stimulating them with a peptide, mixing them with CD8-positive T cells, and then measuring IFN-γ released by CTL against target cells. As the APC, dendritic cells derived from human peripheral blood mononuclear leukocytes can preferably be used. As a reaction system, a transgenic animal prepared to express HLA antigen can also be used. Also, for example, the target cells 51It is possible to calculate the cytotoxic activity of CTLs induced by a peptide from the radioactivity released from target cells radiolabeled with Cr or the like. Alternatively, in the presence of APCs stimulated with the peptide, IFN-γ produced and released by CTLs can be measured, and the CTL-inducing ability can be evaluated by visualizing the inhibition zone on the culture medium using an anti-IFN-γ monoclonal antibody. In addition to the above modifications, the peptide of the present invention can also be linked to other peptides as long as the resulting linked peptide retains the CTL-inducing ability. Examples of suitable peptides to be linked to the peptide of the present invention include CTL-inducing peptides derived from other coronavirus proteins. Also, the peptides of the present invention can be linked to each other. Suitable linkers that can be used for linking peptides are known in the art, and for example, linkers such as AAY (P. M. Daftarian et al., J Trans Med 2007, 5:26), AAA, NKRK (SEQ ID NO: 27) (R. P. M. Sutmuller et al., J Immunol. 2000, 165: 7308-15), or K (S. Ota et al., Can Res. 62, 1471-6, K. S. Kawamura et al., J Immunol. 2002, 168: 5709-15) can be used. Peptides can be linked in various arrangements (e.g., in a chain, in an overlapping manner, etc.), and three or more peptides can also be linked. The peptide of the present invention can also be linked to other substances as long as the resulting linked peptide retains the CTL-inducing ability. Examples of suitable substances to be linked to the peptide of the present invention include, for example, peptides, lipids, sugars or sugar chains, acetyl groups, and natural or synthetic polymers, etc. The peptide of the present invention can also be modified such as glycosylation, side chain oxidation, or phosphorylation as long as the CTL-inducing ability is not impaired. By performing such types of modifications, additional functions (e.g., targeting functions and delivery functions) can be imparted, or the peptide can be stabilized. For example, in order to enhance the in vivo stability of peptides, it is known in the art to introduce D-amino acids, amino acid mimics, or non-natural amino acids, and this concept can also be adapted to the peptides of the present invention. The stability of peptides can be assayed in several ways. For example, stability can be tested using peptidases and various biological media such as human plasma and serum (see, for example, Verhoef et al., Eur J Drug Metab Pharmacokin 1986, 11: 291-302). Furthermore, as described above, among the modified peptides in which one, two, or several amino acid residues are substituted, deleted, inserted, and / or added, those having the same or higher activity compared to the original peptide can be screened or selected. Thus, the present invention also provides a method for screening or selecting a modified peptide having the same or higher activity compared to the original one. Specifically, the present invention provides a method for screening a peptide having CTL-inducing ability, which includes the following steps: (a) Creating a candidate sequence consisting of an amino acid sequence in which one, two, or several amino acid residues are substituted, deleted, inserted, and / or added to the original amino acid sequence consisting of an amino acid sequence selected from SEQ ID NOs: 1, 2, 3, 4, 5, 7, 9, 10, 11, 12, 13, 14, and 15; (b) Selecting candidate sequences that do not have significant homology (sequence identity) with any known human gene products from the candidate sequences created in (a); (c) Contacting a peptide consisting of the candidate sequence selected in (b) with an APC; (d) Contacting the APC of (c) with CD8-positive T cells; and (e) Selecting a peptide having CTL-inducing ability equal to or higher than that of the peptide consisting of the original amino acid sequence. In one embodiment, the APC for contacting with the peptide is an APC that is positive for either or both of HLA-A02 and HLA-A24. In this specification, the peptides of the present invention are also described as "SARS-CoV-2 peptides" or "SARS-CoV-2 polypeptides". In certain embodiments of the present invention, a portion of the TCR can also include one, two, or three complementarity determining regions (CDRs) of either or both of the α-chain and β-chain of the TCR. In preferred embodiments, a portion of the TCR includes the CDR3 of either or both of the α-chain and β-chain of the TCR. The preferred amino acid sequences of the CDR3s identified in the present invention are as follows: The CDR3 of the human T cell receptor α-chain specified by any amino acid sequence selected from the group consisting of SEQ ID NOs: 32, 34, 36, and 38, and The CDR3 of the human T cell receptor β-chain specified by any amino acid sequence selected from the group consisting of SEQ ID NOs: 33, 35, 37, and 39. In certain embodiments of the present invention, the amino acid sequences of the CDR3s of the T cell receptor α-chain and the T cell receptor β-chain can be combined, for example, as follows: CDR3 of T cell receptor α-chain CDR3 of T cell receptor β-chain SEQ ID NO: 32 SEQ ID NO: 33, SEQ ID NO: 34 SEQ ID NO: 35, SEQ ID NO: 36 SEQ ID NO: 37, and SEQ ID NO: 38 SEQ ID NO: 39. Furthermore, CDR3s including conservative modifications are also included in the CDR3s of the present invention. However, the peptides of the present invention are not limited thereto and can include non-conservative modifications as long as the modified CDR3 retains the function of the original CDR3. In the present invention, when the antigen recognition specificity similar to that of the TCR from which the original CDR3 is derived is imparted to the transplanted TCR, it means that the original function of CDR3 is retained in the modified CDR3. Such specific recognition can be confirmed by any known method, and preferred methods include, for example, a tetramer assay using HLA molecules and a peptide administered to the subject from which the TCR was obtained (e.g., Altman et al. Science. 1996, 274, 94-6; McMichael et al. J Exp Med. 1998, 187, 1367-71), as well as an ELISPOT assay. By performing the ELISPOT assay, it can be confirmed that T cells expressing TCR on the cell surface recognize cells by the TCR, and signals are transmitted intracellularly, and then cytokines such as IFN-γ are released from the T cells. Using methods well-known in the art, the cytotoxic activity of T cells against target cells can be examined. Preferred methods include, for example, a chromium release assay using HLA-positive cells infected with coronavirus as target cells. III. Preparation of the Peptide of the Present Invention The peptide of the present invention can be prepared using well-known techniques. For example, the peptide of the present invention can be prepared using recombinant DNA technology or chemical synthesis. The peptide of the present invention can be synthesized individually or as a longer polypeptide containing two or more peptides. After production in a host cell using recombinant DNA technology or after chemical synthesis, the peptide of the present invention can be isolated from the host cell or the synthetic reactant. That is, the peptide of the present invention can be purified or isolated so as to be substantially free of other host cell proteins and their fragments or any other chemical substances. The peptide of the present invention may include modifications such as glycosylation, side chain oxidation, or phosphorylation, as long as the biological activity of the original peptide is not impaired by the modification. Other exemplary modifications include the incorporation of D-amino acids or other amino acid mimics, which can be used, for example, to extend the serum half-life of the peptide. The peptide of the present invention can be obtained by chemical synthesis based on the selected amino acid sequence. Examples of conventional peptide synthesis methods that can be adapted for this synthesis include the methods described in the following documents: (i) Peptide Synthesis, Interscience, New York, 1966; (ii) The Proteins, Vol. 2, Academic Press, New York, 1976; (iii) "Peptide Synthesis" (in Japanese), Maruzen, 1975; (iv) "Fundamentals and Experiments of Peptide Synthesis" (in Japanese), Maruzen, 1985; (v) "Development of Pharmaceuticals" (in Japanese), Continued Volume 14 (Peptide Synthesis), Hirokawa Shoten, 1991; (vi) WO99 / 67288; and (vii) Barany G. & Merrifield R.B., Peptides Vol. 2, Solid Phase Peptide Synthesis, Academic Press, New York, 1980, 100-18. Alternatively, any known genetic engineering method for producing a peptide can be adapted to obtain the peptide of the present invention (for example, Morrison J, J Bacteriology 1977, 132: 349-51; Clark-Curtiss & Curtiss, Methods in Enzymology (Wu et al.) 1983, 101: 347-62). For example, first, an appropriate vector containing a polynucleotide encoding the peptide of the present invention in an expressible form (for example, downstream of a regulatory sequence corresponding to a promoter sequence) is prepared and transformed into an appropriate host cell. Then, the host cell is cultured to produce the peptide of the present invention. Alternatively, the peptide of the present invention can also be produced in vitro using an in vitro translation system. IV. Polynucleotide The present invention also provides a polynucleotide encoding any of the peptides of the present invention. These include polynucleotides derived from the native SARS-CoV-2 gene (e.g., GenBank accession number MN908947 (SEQ ID NO: 16)), and polynucleotides having a conservatively modified nucleotide sequence thereof. As used herein, the phrase "conservatively modified nucleotide sequence" refers to a sequence that encodes the same or essentially the same amino acid sequence. Due to the degeneracy of the genetic code, numerous functionally identical nucleic acids encode any given protein. For example, the codons GCA, GCC, GCG, and GCU all encode the amino acid alanine. Thus, at any position where an alanine is specified by a codon, the codon can be changed to any of the corresponding codons without changing the encoded polypeptide. Such nucleic acid mutations are "silent mutations" and are a type of conservatively modified mutation. Every nucleic acid sequence herein that encodes a peptide also represents every possible silent mutation of that nucleic acid. One of ordinary skill in the art will recognize that each codon in a nucleic acid (except for AUG, which is typically the only codon for methionine, and TGG, which is typically the only codon for tryptophan) can be modified to obtain a functionally identical molecule. Thus, each silent mutation of a nucleic acid encoding a peptide is implicitly described in each disclosed sequence. The polynucleotides of the present invention can be composed of DNA, RNA, and derivatives thereof. DNA is appropriately composed of bases such as A, T, C, and G, and in RNA, T is replaced by U. The polynucleotides of the present invention may encode a plurality of peptides of the present invention, with or without intervening amino acid sequences. For example, the intervening amino acid sequence may provide a cleavage site (e.g., an enzyme recognition sequence) for the polynucleotide or the translated peptide. Further, the polynucleotide may include any additional sequences relative to the coding sequence encoding the peptide of the present invention. For example, the polynucleotide may be a recombinant polynucleotide including regulatory sequences necessary for the expression of the peptide, or may be an expression vector (e.g., a plasmid) having a marker gene or the like. Generally, such recombinant polynucleotides can be prepared by manipulating the polynucleotide by conventional recombinant techniques, such as using polymerases and endonucleases. The polynucleotides of the present invention can be produced using either recombinant techniques or chemical synthesis techniques. For example, a polynucleotide can be produced by inserting it into an appropriate vector, which can be expressed when transfected into competent cells. Alternatively, the polynucleotide can also be amplified using PCR techniques or expression in an appropriate host (see, for example, Sambrook et al., Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratory, New York, 1989). Alternatively, the polynucleotide can also be synthesized using solid-phase techniques described in Beaucage SL & Iyer RP, Tetrahedron 1992, 48: 2223-311; Matthes et al., EMBO J 1984, 3: 801-5. V. Exosome The present invention further provides intracellular vesicles called exosomes that present on their surface a complex formed between the peptide of the present invention and an HLA antigen. Exosomes can be prepared using, for example, the methods detailed in Japanese Patent Publication No. 11-510507 and WO99 / 03499, and can be prepared using APCs obtained from a patient to be treated and / or prevented. The exosomes of the present invention can be inoculated as a vaccine in the same manner as the peptide of the present invention. The type of HLA antigen contained in the complex must match that of the subject in need of treatment and / or prevention. For example, in Asian countries including Japan, HLA-A24 (e.g., HLA-A * 24:02), in Europe and America, HLA-A02 (e.g., HLA-A * 02:01, or HLA-A * 02:06) are widely common alleles, and these types of HLA antigens are considered suitable for the treatment of Asian or Caucasian patients. Typically, in a clinic, by preliminarily examining the type of HLA antigen of a patient in need of treatment, an appropriate selection of a peptide having a high level of binding affinity for a specific HLA antigen or having the ability to induce CTL by antigen presentation via a specific HLA antigen becomes possible. The exosomes of the present invention present on their surface a complex of the peptide of the present invention and HLA-A24 or HLA-A02. When the HLA forming the complex with the peptide of the present invention is HLA-A02, the peptide of the present invention is preferably a peptide having an amino acid sequence selected from SEQ ID NOs: 1, 2, 3, 4, 5, 7, 9, 10, 11, 12, 13, 14, and 15 or a modified peptide thereof, and more preferably a peptide consisting of an amino acid sequence selected from SEQ ID NOs: 1, 2, 3, 4, 5, 7, 9, 10, 11, 12, 13, 14, and 15 or a modified peptide thereof. When the HLA that forms a complex with the peptide of the present invention is HLA-A24, the peptide of the present invention is preferably a peptide having an amino acid sequence selected from SEQ ID NOs: 3 and 11 or a modified peptide thereof, and more preferably a peptide consisting of an amino acid sequence selected from SEQ ID NOs: 3 and 11 or a modified peptide thereof. VI. Antigen-presenting cells (APC) The present invention also provides an APC that presents on its surface a complex formed between an HLA antigen and the peptide of the present invention. Alternatively, the present invention provides an APC having on its cell surface a complex formed between an HLA antigen and the peptide of the present invention. The APC of the present invention can be an isolated APC. When used with respect to cells (such as APC, CTL, etc.), the term "isolated" refers to the fact that the cells are separated from other types of cells. The APC of the present invention may be derived from APCs from a patient to be treated and / or prevented, and can be administered as a vaccine alone or in combination with other drugs including the peptide, exosomes, or CTL of the present invention. The APC of the present invention is not limited to a specific type of cell, and includes cells known to present protein antigens on their cell surfaces so as to be recognized by lymphocytes, such as dendritic cells (DC), Langerhans cells, macrophages, B cells, and activated T cells. Since DC is a representative APC having the most potent CTL-inducing action among APCs, DC can be preferably used as the APC of the present invention. For example, the APC of the present invention can be obtained by inducing DC from peripheral blood monocytes and then stimulating them with the peptide of the present invention in vitro, ex vivo, or in vivo. When the peptide of the present invention is administered to a subject, APCs presenting the peptide of the present invention are induced in the body of the subject. Therefore, the APC of the present invention can be obtained by recovering APCs from the subject after administering the peptide of the present invention to the subject. Alternatively, the APC of the present invention can also be obtained by contacting the APCs recovered from the subject with the peptide of the present invention. In a subject, in order to induce an immune response against coronavirus-infected cells, the APCs of the present invention can be administered to the subject alone or in combination with other agents including the peptides, exosomes, or CTLs of the present invention. For example, ex vivo administration may include the following steps: (a) recovering APCs from a first subject; (b) contacting the APCs of step (a) with a peptide; and (c) administering the APCs of step (b) to a second subject. The first subject and the second subject may be the same individual or different individuals. When the first subject and the second subject are different individuals, it is preferable that the HLAs of the first subject and the second subject are of the same type. The APCs obtained by the above step (b) can be a vaccine for treating and / or preventing coronavirus infection. In one embodiment, the method of the present invention can further additionally include a step of recovering the APCs after step (b). The recovered APCs can then be administered to the second subject. The APCs of the present invention obtained by the method as described above have the ability to induce CTLs. The term "CTL-inducing ability" used with respect to APCs refers to the ability of an APC to induce CTLs when contacted with CD8-positive T cells. The CTLs induced by the APCs of the present invention are CTLs specific for SARS-CoV-2 proteins and exhibit specific cytotoxic activity against SARS-CoV-2-infected cells. In addition to the above method, the APC of the present invention can also be prepared by introducing a polynucleotide encoding the peptide of the present invention into APC in vitro. The polynucleotide to be introduced may be in the form of DNA or RNA. Examples of the introduction method include, without particular limitation, various methods conventionally practiced in the art, such as lipofection, electroporation, and calcium phosphate method. More specifically, methods such as those described in Cancer Res 1996, 56: 5672-7; J Immunol 1998, 161: 5607-13; J Exp Med 1996, 184: 465-72; Published Patent Gazette No. 2000-509281 can be used. By introducing a polynucleotide encoding the peptide of the present invention into APC, the polynucleotide undergoes transcription, translation, etc. intracellularly, and then the resulting peptide is processed by MHC class I, and the peptide of the present invention is presented on the cell surface of APC through the presentation pathway. In a preferred embodiment, the APC of the present invention is an APC that presents a complex formed between HLA-A02 (more preferably HLA-A * 02:01 or HLA-A * 02:06) and the peptide of the present invention on its own cell surface. When the HLA forming a complex with the peptide of the present invention is HLA-A02, the peptide of the present invention is preferably a peptide having an amino acid sequence selected from SEQ ID NOs: 1, 2, 3, 4, 5, 7, 9, 10, 11, 12, 13, 14, and 15 or a modified peptide thereof, and more preferably a peptide consisting of an amino acid sequence selected from SEQ ID NOs: 1, 2, 3, 4, 5, 7, 9, 10, 11, 12, 13, 14, and 15. Alternatively, in a preferred embodiment, the APC of the present invention is HLA-A24 (more preferably HLA-A *An APC that presents a complex formed between HLA-A24:02) and the peptide of the present invention on its own cell surface. When the HLA forming a complex with the peptide of the present invention is HLA-A24, the peptide of the present invention is preferably a peptide having an amino acid sequence selected from SEQ ID NOs: 3 and 11 or a modified peptide thereof, and more preferably a peptide consisting of an amino acid sequence selected from SEQ ID NOs: 3 and 11. Also, the APC of the present invention is preferably an APC induced by a method including the following step (a) or (b): (a) contacting an APC expressing HLA-A02 (more preferably HLA-A * 02:01 or HLA-A * 02:06) or HLA-A24 (more preferably HLA-A * 24:02) with the peptide of the present invention; (b) introducing a polynucleotide encoding the peptide of the present invention into an APC expressing HLA-A02 (more preferably HLA-A * 02:01 or HLA-A * 02:06) or HLA-A24 (more preferably HLA-A * 24:02). The peptide of the present invention that contacts an APC expressing HLA-A02 is preferably a peptide having an amino acid sequence selected from SEQ ID NOs: 1, 2, 3, 4, 5, 7, 9, 10, 11, 12, 13, 14, and 15 or a modified peptide thereof, and more preferably a peptide consisting of an amino acid sequence selected from SEQ ID NOs: 1, 2, 3, 4, 5, 7, 9, 10, 11, 12, 13, 14, and 15. The peptide of the present invention that contacts an APC expressing HLA-A24 is preferably a peptide having an amino acid sequence selected from SEQ ID NOs: 3 and 11 or a modified peptide thereof, and more preferably a peptide consisting of an amino acid sequence selected from SEQ ID NOs: 3 and 11. In addition, according to the present invention, there is provided the use of the peptide of the present invention for producing a pharmaceutical composition that induces an APC having CTL-inducing ability. In addition, the present invention provides a method or process for producing a pharmaceutical composition that induces an APC having CTL-inducing ability. Furthermore, the present invention also provides the peptide of the present invention for inducing an APC having CTL-inducing ability. VII. Cytotoxic T Lymphocytes (CTL) The CTL induced by the peptide of the present invention can be used as a vaccine in the same manner as the peptide of the present invention in order to enhance the immune response targeting coronavirus-infected cells in vivo. Therefore, the present invention provides CTL induced or activated by the peptide of the present invention. The CTL of the present invention is a CTL that targets the peptide of the present invention and is a CTL that can bind to the complex of the peptide of the present invention and the HLA antigen. The binding of CTL to the complex is carried out via the T cell receptor (TCR) present on the cell surface of CTL. The CTL of the present invention can be an isolated CTL. ​The CTL of the present invention can be obtained by: (1) administering the peptide of the present invention to a subject; (2) stimulating APCs, CD8-positive T cells, or peripheral blood mononuclear cells (PBMCs) derived from a subject with the peptide of the present invention in vitro; (3) contacting CD8-positive T cells or PBMCs with APCs or exosomes that present a complex of an HLA antigen and the peptide of the present invention on their surface in vitro; or (4) introducing a vector containing a polynucleotide encoding each subunit of a T cell receptor (TCR) capable of binding to the peptide of the present invention presented by an HLA antigen on the cell surface into CD8-positive T cells. The exosomes and APCs used in the methods (2) or (3) above can be prepared by the methods described in the chapters of "V. Exosomes" and "VI. Antigen-presenting cells (APCs)", respectively. The details of the method (4) above are described in the chapter of "VIII. T cell receptor (TCR)". In one embodiment, the method of the present invention can further include a step of recovering the CTL induced after each step. The CTL of the present invention can be administered alone to a patient to be treated and / or prevented, or in combination with other drugs containing the peptide, APC, or exosome of the present invention for the purpose of modulating the effect. Further, the CTL of the present invention can be a CTL induced from CD8-positive T cells derived from a patient to whom the CTL is to be administered. The CTL of the present invention specifically acts on target cells that present the peptide of the present invention, for example, the same peptide used for the induction of the CTL of the present invention. The target cells may be cells that endogenously express SARS-CoV-2 protein, such as coronavirus-infected cells, or cells transfected with the SARS-CoV-2 gene. Cells that present the peptide on the cell surface by stimulation with the peptide of the present invention can also be targets for the attack of the CTL of the present invention. Further, the target cells of the CTL of the present invention are preferably HLA-A02 (more preferably HLA-A * 02:01 or HLA-A * 02:06) or HLA-A24 (more preferably HLA-A* It is a positive cell. In a preferred embodiment, the CTL of the present invention specifically targets cells expressing both HLA-A02 (more preferably HLA-A * 02:01 or HLA-A * 02:06) or HLA-A24 (more preferably HLA-A * 24:02) and the SARS-CoV-2 protein. As used herein, when a CTL "targets" a cell, it means that the CTL recognizes a cell presenting a complex of HLA and the peptide of the present invention on its cell surface and exhibits cytotoxic activity against the cell. Also, "specifically targets" means that the CTL exhibits cytotoxic activity against the cell but not against other cells. Also, in the context of CTL, the term "recognizes a cell" refers to binding via its TCR to a complex formed between HLA presented on the cell surface and the peptide of the present invention, and exhibiting specific cytotoxic activity against the cell. Thus, the CTL of the present invention preferably binds via its TCR to a complex formed between HLA-A02 (more preferably HLA-A * 02:01 or HLA-A * 02:06) or HLA-A24 (more preferably HLA-A * 24:02) presented on the cell surface and the peptide of the present invention. Also, the CTL of the present invention is preferably a CTL induced by a method comprising the following step (a) or (b): (a) contacting CD8-positive T cells in vitro with an APC or exosome presenting on its surface a complex of HLA-A02 (more preferably HLA-A * 02:01 or HLA-A * 02:06) or HLA-A24 (more preferably HLA-A * 24:02) and the peptide of the present invention; (b) introducing into CD8-positive T cells an APC or exosome presenting on its cell surface a complex of HLA-A02 (more preferably HLA-A * 02:01 or HLA-A *02:06) or HLA-A24 (more preferably HLA-A * introducing a polynucleotide encoding each subunit of a TCR that can bind to the peptide of the present invention presented by 24:02). VIII. T cell receptor (TCR) The present invention also provides a composition comprising a polynucleotide encoding each subunit of a TCR that can bind to the peptide of the present invention presented by an HLA antigen on the cell surface, and a method of using the same. By expressing a TCR that can bind to the peptide of the present invention presented on the cell surface by an HLA antigen, the polynucleotide confers specificity for coronavirus-infected cells to CD8-positive T cells. By using methods known in the art, polynucleotides encoding the α-chain and β-chain as TCR subunits of CTLs induced by the peptide of the present invention can be identified (WO2007 / 032255, and Morgan et al., J Immunol, 171, 3288 (2003)). For example, the PCR method is preferred for analyzing TCRs. PCR primers for analysis may be, for example, a 5'-R primer (5'-gtctaccaggcattcgcttcat-3') (SEQ ID NO: 28) as a 5'-side primer, and a 3-TRa-C primer (5'-tcagctggaccacagccgcagcgt-3') (SEQ ID NO: 29) specific for the C region of the TCRα chain, a 3-TRb-C1 primer (5'-tcagaaatcctttctcttgac-3') (SEQ ID NO: 30) specific for the C1 region of the TCRβ chain, or a 3-TRβ-C2 primer (5'-ctagcctctggaatcctttctctt-3') (SEQ ID NO: 31) specific for the C2 region of the TCRβ chain, but are not limited thereto. The TCR formed by introducing the identified polynucleotide into CD8-positive T cells can bind to target cells presenting the peptide of the present invention with high binding affinity, and mediates efficient killing of target cells presenting the peptide of the present invention in vivo and in vitro. The polynucleotides encoding each subunit of the TCR can be incorporated into a suitable vector, such as a retroviral vector. These vectors are well-known in the art. The polynucleotides or vectors containing them in an expressible form can be introduced into CD8-positive T cells, such as CD8-positive T cells derived from a patient. The present invention provides a ready-made composition that enables the rapid and easy production of modified T cells with excellent coronavirus-infected cell killing properties by the rapid modification of the patient's own T cells (or T cells derived from another subject). As used herein, a specific TCR, when present on the surface of a CD8-positive T cell, specifically recognizes the complex of the peptide of the present invention and the HLA antigen presented on the surface of a target cell, and can confer specific cytotoxic activity against the target cell. Specific recognition of the above complex can be confirmed by any known method, and preferred examples thereof include HLA multimer staining analysis using HLA molecules and the peptide of the present invention, and the ELISPOT assay method. By performing the ELISPOT assay, it can be confirmed that the T cells transfected with the above polynucleotide specifically recognize the target cells by the TCR and that the signal is transmitted intracellularly. When the above TCR is present on the surface of a CD8-positive T cell, the confirmation that the TCR can confer target cell-specific cytotoxic activity on the CD8-positive T cell can also be performed by a known method. Preferred methods include, for example, measuring the cytotoxic activity against target cells by the chromium release assay method and the like. The present invention also provides CTLs prepared by transducing CD8-positive T cells with polynucleotides encoding each subunit of a TCR that binds to a peptide having an amino acid sequence selected from, for example, SEQ ID NOs: 1, 2, 3, 4, 5, 7, 9, 10, 11, 12, 13, 14, and 15 in relation to HLA-A02. In relation to HLA-A24, CTLs prepared by transducing CD8-positive T cells with polynucleotides encoding each subunit of a TCR that binds to a peptide having an amino acid sequence selected from, for example, SEQ ID NOs: 3 and 11 are provided. The transduced CTLs can home in vivo and can be expanded by well-known in vitro culture methods (e.g., Kawakami et al., J Immunol., 142, 3452-61 (1989)). The CTLs of the present invention can be used to form an immunogenic composition useful for the treatment or prevention of diseases in patients in need of treatment or prevention (see WO2006 / 031221, the content of which is incorporated herein by reference). The present invention relates to a TCR expressed by T cells that recognize SARS-CoV-2-derived peptides. The TCR is a protein molecule composed of a dimer of an α-chain and a β-chain. Human T cells recognize peptides presented on MHC class I (also known as HLA, Human Leukocyte Antigen) molecules through the TCR. As a result, induction of T cell proliferation, differentiation, cytokine production, or secretion of cytotoxic substances (perforin and granzyme) etc. is induced. The TCR-α gene includes a Vα gene, a Jα gene, and a Cα gene. The TCR-β gene includes a Vβ gene, a Dβ gene, a Jβ gene, and a Cβ gene. The region that determines the specificity of the TCR for a peptide is called the Complementarity Determining Region (CDR), and CDR1, CDR2, and CDR3 exist. Among them, since CDR3 directly contacts the peptide, its amino acid sequence is very important in determining the antigen recognition specificity of the TCR. In the TCR-α chain, the V-J interval corresponds to CDR3, and in the TCR-β chain, the V-D and D-J intervals correspond to CDR3, and diversity occurs due to base insertions and deletions. Alternatively, in certain embodiments of the present invention, a portion of the TCR can also include one, two, or three complementarity determining regions (CDRs) of either or both of the α-chain and the β-chain of the TCR. In a preferred embodiment, a portion of the TCR includes CDR3 of either or both of the α-chain and the β-chain of the TCR. The preferred amino acid sequences of CDR3 identified in the present invention are as follows; The CDR3 of the human T cell receptor α chain specified by any amino acid sequence selected from the group consisting of SEQ ID NOs: 32, 34, 36, and 38, and the CDR3 of the human T cell receptor β chain specified by any amino acid sequence selected from the group consisting of SEQ ID NOs: 33, 35, and 39. In one aspect of the present invention, the amino acid sequences of the CDR3 of the T cell receptor α chain and the T cell receptor β chain can be combined, for example, as follows: CDR3 of T cell receptor α chain CDR3 of T cell receptor β chain SEQ ID NO: 32 SEQ ID NO: 33, SEQ ID NO: 34 SEQ ID NO: 35, SEQ ID NO: 36 SEQ ID NO: 37, and SEQ ID NO: 38 SEQ ID NO: 39 In one aspect, the α chain, β chain, TCR consisting of them, and polynucleotide encoding them of the TCR of the present invention can be isolated. IX. Pharmaceutical Composition The present invention also provides a composition or pharmaceutical composition comprising at least one active ingredient selected from the following: (a) The peptide of the present invention; (b) A polynucleotide encoding the peptide of the present invention in an expressible form; (c) The APC of the present invention; (d) The exosome of the present invention; (e) The CTL of the present invention. In addition to the above active ingredients, the pharmaceutical composition of the present invention may optionally contain carriers, excipients, etc. commonly used in pharmaceuticals without particular limitation. Examples of carriers that can be used in the pharmaceutical composition of the present invention include sterile water, physiological saline, phosphate buffer solution, culture solution, etc. Therefore, the present invention also provides a pharmaceutical composition comprising at least one active ingredient selected from the following (a) to (e) and a pharmaceutically acceptable carrier: (a) The peptide of the present invention; (b) A polynucleotide encoding the peptide of the present invention in an expressible form; (c) The APC of the present invention; (d) The exosome of the present invention; (e) The CTL of the present invention. Furthermore, the pharmaceutical composition of the present invention may contain, if necessary, a stabilizer, a suspension, a preservative, a surfactant, a solubilizing agent, a pH adjuster, an aggregation inhibitor, etc. The expression of SARS-CoV-2 protein is significantly increased in coronavirus-infected cells compared to non-infected cells. Therefore, the peptide of the present invention or the polynucleotide encoding the peptide can be used for any one or a combination of the purposes of treating, preventing, and suppressing the aggravation of coronavirus infection. Accordingly, the present invention provides a pharmaceutical composition for any one or a plurality of purposes selected from the treatment, prevention, and suppression of aggravation of coronavirus infection, which contains one or more of the peptide or polynucleotide of the present invention as an active ingredient. Alternatively, for use as a pharmaceutical composition, the peptide of the present invention can be presented on the surface of an exosome or an APC. In addition, the CTL of the present invention targeting any one of the peptides of the present invention can also be used as an active ingredient of the pharmaceutical composition of the present invention. The pharmaceutical composition of the present invention may contain a therapeutically effective amount or a pharmaceutically effective amount of the above active ingredient. The pharmaceutical composition of the present invention can also be used as a vaccine. In the context of the present invention, the term "vaccine" (also referred to as "immunogenic composition") refers to a composition having a function of inducing an immune response that provides an anti-infective effect against coronavirus when inoculated into an animal. Therefore, the pharmaceutical composition of the present invention can be used to induce an immune response that provides an anti-infective effect against coronavirus. The immune response induced by the peptide, polynucleotide, APC, CTL, and pharmaceutical composition of the present invention is not particularly limited as long as it is an immune response that provides an anti-infective effect against coronavirus, but illustratively includes the induction of CTL specific to coronavirus-infected cells and the induction of cytotoxic activity specific to coronavirus-infected cells. The pharmaceutical composition of the present invention can be used for any one or a combination of treating, preventing, and suppressing the progression of coronavirus infection in a human subject or patient. The pharmaceutical composition of the present invention can be preferably used for subjects positive for HLA-A02 or HLA-A24. Further, the pharmaceutical composition of the present invention can be preferably used for treating and / or preventing coronavirus infection in a subject having HLA-A02 or HLA-A24, and / or for suppressing the progression of the disease. In another aspect, the present invention also provides the use of an active ingredient selected from the following in the manufacture of a pharmaceutical composition for treating and / or preventing coronavirus infection: (a) The peptide of the present invention; (b) A polynucleotide encoding the peptide of the present invention in an expressible form; (c) An APC presenting the peptide of the present invention on its surface; (d) An exosome presenting the peptide of the present invention on its surface; and (e) The CTL of the present invention. Alternatively, the present invention further provides an active ingredient selected from the following for use in treating and / or preventing coronavirus infection: (a) The peptide of the present invention; (b) A polynucleotide encoding the peptide of the present invention in an expressible form; (c) An APC presenting the peptide of the present invention on its surface; (d) An exosome presenting the peptide of the present invention on its surface; and (e) The CTL of the present invention. Alternatively, the present invention further provides a method or process for manufacturing a pharmaceutical composition for treating and / or preventing coronavirus infection, the method or process comprising formulating at least one active ingredient selected from the following with a pharmaceutically or physiologically acceptable carrier: (a) The peptide of the present invention; (b) A polynucleotide encoding the peptide of the present invention in an expressible form; (c) An APC presenting the peptide of the present invention on its surface; (d) An exosome presenting the peptide of the present invention on its surface; and (e) The CTL of the present invention. In another aspect, the present invention also provides a method or process for manufacturing a pharmaceutical composition for the treatment and / or prevention of coronavirus infection, the method or process comprising mixing an active ingredient selected from the following with a pharmaceutically or physiologically acceptable carrier: (a) The peptide of the present invention; (b) A polynucleotide encoding the peptide of the present invention in an expressible form; (c) An APC presenting the peptide of the present invention on its surface; (d) An exosome presenting the peptide of the present invention on its surface; and (e) The CTL of the present invention. In another aspect, the present invention also provides a method for the treatment and / or prevention of coronavirus infection, the method comprising administering at least one active ingredient selected from the following to a subject: (a) The peptide of the present invention; (b) A polynucleotide encoding the peptide of the present invention in an expressible form; (c) An APC presenting the peptide of the present invention on its surface; (d) An exosome presenting the peptide of the present invention on its surface; and (e) The CTL of the present invention. In the present invention, peptides having an amino acid sequence selected from SEQ ID NOs: 1, 2, 3, 4, 5, 7, 9, 10, 11, 12, 13, 14, and 15 were found to be HLA-A02-restricted epitope peptides capable of inducing a strong and specific immune response. Therefore, a pharmaceutical composition of the present invention containing at least one peptide having an amino acid sequence selected from SEQ ID NOs: 1, 2, 3, 4, 5, 7, 9, 10, 11, 12, 13, 14, and 15 is particularly suitable for administration to a subject having HLA-A02 as an HLA antigen (e.g., HLA-A * 02:01). The same applies to a pharmaceutical composition containing a polynucleotide encoding any of these peptides (i.e., the polynucleotide of the present invention), an APC or exosome presenting these peptides (i.e., the APC or exosome of the present invention), and a CTL targeting these peptides (i.e., the CTL of the present invention). That is, a pharmaceutical composition containing an active ingredient related to a peptide having an amino acid sequence selected from SEQ ID NOs: 1, 2, 3, 4, 5, 7, 9, 10, 11, 12, 13, 14, and 15 is suitable for administration to a subject having HLA-A02 (i.e., an HLA-A02-positive subject). In a more preferred embodiment, the pharmaceutical composition of the present invention is a pharmaceutical composition containing a peptide having an amino acid sequence of SEQ ID NOs: 2, 3, 4, 7, 10, 11, 12, or 15. Alternatively, in the present invention, peptides having an amino acid sequence selected from SEQ ID NOs: 3, 4, 7, 10, 11, 12, and 15 were found to be HLA-A02-restricted epitope peptides capable of inducing a strong and specific immune response. Therefore, a pharmaceutical composition of the present invention containing at least one peptide having an amino acid sequence selected from SEQ ID NOs: 3, 4, 7, 10, 11, 12, and 15 is particularly suitable for administration to a subject having HLA-A02 as an HLA antigen (e.g., HLA-A *It is particularly suitable for administration to a subject having (02:06). The same applies to a pharmaceutical composition comprising a polynucleotide encoding any of these peptides (i.e., the polynucleotide of the present invention), an APC or exosome presenting these peptides (i.e., the APC or exosome of the present invention), and a CTL targeting these peptides (i.e., the CTL of the present invention). That is, a pharmaceutical composition comprising an active ingredient related to a peptide having an amino acid sequence selected from SEQ ID NOs: 3, 4, 7, 10, 11, 12, and 15 is suitable for administration to a subject having HLA-A02 (i.e., an HLA-A02 positive subject). In a more preferred embodiment, the pharmaceutical composition of the present invention is a pharmaceutical composition comprising a peptide having the amino acid sequence of SEQ ID NO: 3, 4, 7, 10, 11, 12 or 15. Similarly, in the present invention, peptides having an amino acid sequence selected from SEQ ID NOs: 3 and 11 were found as HLA-A24-restricted epitope peptides capable of inducing a strong and specific immune response. Therefore, a pharmaceutical composition of the present invention comprising at least one peptide having an amino acid sequence selected from SEQ ID NOs: 3 and 11 is particularly suitable for administration to a subject having HLA antigen HLA-A24 (e.g., HLA-A * 24:02). The same applies to a pharmaceutical composition comprising a polynucleotide encoding any of these peptides (i.e., the polynucleotide of the present invention), an APC or exosome presenting these peptides (i.e., the APC or exosome of the present invention), and a CTL targeting these peptides (i.e., the CTL of the present invention). That is, a pharmaceutical composition comprising an active ingredient related to a peptide having an amino acid sequence selected from SEQ ID NOs: 3 and 11 is suitable for administration to a subject having HLA-A24 (i.e., an HLA-A24 positive subject). In a more preferred embodiment, the pharmaceutical composition of the present invention is a pharmaceutical composition comprising a peptide having the amino acid sequences of SEQ ID NOs: 3 and 11. The viral infections treated and / or prevented by the pharmaceutical composition of the present invention are not particularly limited as long as they are coronavirus infections, and coronaviruses include SARS-CoV-2, MERS-CoV, SARS-CoV, and the like. In addition to the aforementioned active ingredient, the pharmaceutical composition of the present invention may further contain other peptides having the ability to induce CTL against coronavirus-infected cells (for example, other CTL-inducing peptides derived from viral structural proteins or non-structural proteins of SARS-CoV-2, MERS-CoV, and SARS-CoV), other polynucleotides encoding the other peptides, other cells presenting the other peptides, and the like. The pharmaceutical composition of the present invention may optionally contain other therapeutic substances as active ingredients as long as the anti-infective effect of the above active ingredients such as the peptide of the present invention against coronavirus is not inhibited. For example, the pharmaceutical composition of the present invention may optionally contain anti-inflammatory compositions, analgesics, chemotherapeutic agents including antiviral agents, and the like. In addition to including other therapeutic substances in the pharmaceutical composition of the present invention itself, the pharmaceutical composition of the present invention can also be administered continuously or simultaneously with one or more other pharmaceutical compositions. The dosage of the pharmaceutical composition of the present invention and other pharmaceutical compositions depends, for example, on the type of pharmaceutical composition used, the disease to be treated, and the schedule and route of administration. It should be understood that in addition to the components specifically mentioned herein, the pharmaceutical composition of the present invention may also contain other components conventional in the art, taking into account the type of formulation. The present invention also provides a product or kit containing the pharmaceutical composition of the present invention. The product or kit of the present invention may include a container containing the pharmaceutical composition of the present invention. Examples of suitable containers include, but are not limited to, bottles, vials, and test tubes. The container can be formed from various materials such as glass or plastic. The container may be labeled, and the label can describe the disease or disease state for which the pharmaceutical composition of the present invention should be used. The label can also indicate instructions regarding administration and the like. In addition to a container containing the pharmaceutical composition of the present invention, the product or kit of the present invention may further optionally include a second container containing a pharmaceutically acceptable diluent. The product or kit of the present invention may further include other materials that are desirable from a commercial and user perspective, such as other buffers, diluents, filters, syringes, needles, and an accompanying document describing instructions for use. Optionally, the pharmaceutical composition of the present invention can be provided in a pack or dispenser device that may contain one or more unit dosage forms containing the active ingredient. The pack may include, for example, a metal foil or plastic foil such as a blister pack. A pack or dispenser device may be accompanied by instructions for administration. (1) A pharmaceutical composition containing a peptide as an active ingredient The pharmaceutical composition containing the peptide of the present invention can be formulated by conventional formulation methods if necessary. The pharmaceutical composition of the present invention may, in addition to the peptide of the present invention, optionally contain carriers, excipients, etc. commonly used in pharmaceuticals without particular limitation. Examples of carriers that can be used in the pharmaceutical composition of the present invention include sterile water (e.g., water for injection), physiological saline, phosphate buffer, phosphate buffered saline, Tris buffered saline, 0.3% glycine, culture medium, etc. Furthermore, the pharmaceutical composition of the present invention may optionally contain stabilizers, suspensions, preservatives, surfactants, solubilizing agents, pH adjusters, aggregation inhibitors, etc. Since the pharmaceutical composition of the present invention can induce specific immunity against coronavirus-infected cells, it can be used for the purpose of treating or preventing coronavirus infections. For example, the pharmaceutical composition of the present invention can be dissolved in a pharmaceutically or physiologically acceptable water-soluble carrier such as sterile water (e.g., water for injection), physiological saline, phosphate buffer, phosphate buffered saline, Tris buffered saline, etc. If necessary, after adding a stabilizer, suspension, preservative, surfactant, solubilizing agent, pH adjuster, aggregation inhibitor, etc., the peptide solution can be prepared by sterilizing the peptide solution. The sterilization method of the peptide solution is not particularly limited, but it is preferably carried out by filtration sterilization. Filtration sterilization can be carried out using, for example, a filtration sterilization filter with a pore size of 0.22 μm or less. The peptide solution after filtration sterilization can be administered to a subject as, for example, an injection, although not limited thereto. Further, the pharmaceutical composition of the present invention may be prepared as a lyophilized preparation by lyophilizing the above peptide solution. The lyophilized preparation can be prepared by filling the peptide solution prepared as described above into a suitable container such as an ampoule, vial, or plastic container, then performing lyophilization, and sealing the container with a rubber stopper or the like that has been sterilized and washed after decompression. The lyophilized preparation can be administered to a subject after being redissolved in a pharmaceutically or physiologically acceptable water-soluble carrier such as sterile water (e.g., water for injection), physiological saline, phosphate buffer, phosphate buffered saline, Tris buffered saline, etc. before administration. Preferred examples of the pharmaceutical composition of the present invention include injections of such filtration-sterilized peptide solutions and lyophilized preparations obtained by lyophilizing the peptide solution. Furthermore, a kit containing such a lyophilized preparation and a redissolution solution is also included in the present invention. Also included in the present invention is a kit containing a container containing the lyophilized preparation that is the pharmaceutical composition of the present invention and a container containing its redissolution solution. The pharmaceutical composition of the present invention can also contain two or more types of combinations of the peptides of the present invention. The combination of peptides may take the form of a cocktail in which the peptides are mixed, or the peptides may be bound to each other using standard techniques. For example, the peptides may be chemically bound or expressed as a single fusion polypeptide sequence. By administering the peptide of the present invention, the peptide is presented at a high density on the APC by the HLA antigen, and then CTLs that specifically react with the complex formed between the presented peptide and the HLA antigen are induced. Alternatively, APCs (e.g., DCs) are removed from the subject and then stimulated with the peptide of the present invention to obtain APCs that present any of the peptides of the present invention on their cell surface. These APCs are readministered to the subject to induce CTLs in the subject, and as a result, the aggressiveness against coronavirus-infected cells can be increased. There is a possibility that neutralizing antibodies lose their infection-preventing function due to mutations in their target epitopes (viral immune escape). In general, monoclonal antibodies that rely on antigen-binding specificity for a single epitope are particularly affected by antigen mutations. On the other hand, when multiple CTL epitopes are included (cocktail), even if any one of the epitopes mutates, CTLs that recognize other epitopes are effective. The mixing of epitopes derived from multiple proteins can be said to be an effective strategy for avoiding a decrease in the therapeutic effect due to viral immune escape. The pharmaceutical composition of the present invention may also contain an adjuvant known to efficiently establish cellular immunity. An adjuvant refers to a compound that enhances the immune response to an antigen when administered together with (or sequentially to) an antigen having immunological activity. As the adjuvant, for example, known ones described in documents such as Clin Microbiol Rev 1994, 7: 277-89 can be used. Examples of suitable adjuvants include aluminum salts (aluminum phosphate, aluminum hydroxide, aluminum oxyhydroxide, etc.), alum, cholera toxin, salmonella toxin, incomplete Freund's adjuvant (IFA), complete Freund's adjuvant (CFA), ISCOMatrix, GM-CSF and other immunostimulatory cytokines, oligodeoxynucleotides containing CpG motifs (such as CpG7909), oil-in-water emulsions, saponin or its derivatives (such as QS21), lipopolysaccharides such as lipid A or its derivatives (MPL, RC529, GLA, E6020, etc.), lipopeptides, lactoferrin, flagellin, double-stranded RNA or its derivatives (such as poly IC), bacterial DNA, imidazoquinolines (imiquimod, R848, etc.), C-type lectin ligands (such as trehalose-6,6'-dibehenate: TDB), CD1d ligands (such as α-galactosylceramide), squalene emulsions (MF59, AS03, AF03, etc.), PLGA, etc., but are not limited thereto. In certain embodiments, the pharmaceutical composition of the present invention can contain an amount of adjuvant sufficient to stimulate an immune response. The adjuvant may be contained in a container separate from the pharmaceutical composition containing the peptide of the present invention in a kit containing the pharmaceutical composition of the present invention. In this case, the adjuvant and the pharmaceutical composition may be administered to the subject sequentially or may be mixed immediately before administration to the subject. A kit containing such a pharmaceutical composition containing the peptide of the present invention and an adjuvant is also provided by the present invention. When the pharmaceutical composition of the present invention is a lyophilized preparation, the kit can further contain a reconstitution solution. The present invention also provides a kit comprising a container containing the pharmaceutical composition of the present invention and a container containing the adjuvant.The kit may further include a container storing a reconstitution solution, if necessary. When an oily adjuvant is used as the adjuvant, the pharmaceutical composition of the present invention may be prepared as an emulsion. The emulsion can be prepared, for example, by mixing and stirring the peptide solution prepared as described above and the oily adjuvant. The peptide solution may be one reconstituted after lyophilization. The emulsion may be either a W / O type emulsion or an O / W type emulsion, but a W / O type emulsion is preferably used to obtain a high immune response enhancing effect. IFA can be preferably used as the oily adjuvant, but is not limited thereto. The preparation of the emulsion may be carried out immediately before administration to the subject. In this case, the pharmaceutical composition of the present invention may be provided as a kit containing the peptide solution of the present invention and the oily adjuvant. When the pharmaceutical composition of the present invention is a lyophilized preparation, the kit can further contain a reconstitution solution. The adjuvant for combination with the peptide to be administered is usually formulated in an amount sufficient for immunological stimulation. Alternatively, the peptide can be administered together with an adjuvant in an amount sufficient for immunological stimulation. In certain embodiments, an adjuvant in an amount effective to enhance the immune response to the peptide in the subject can be formulated with the peptide or administered to the subject together with the peptide. Further, the pharmaceutical composition of the present invention may be a liposome preparation encapsulating the peptide of the present invention, a particulate preparation in which the peptide is bound to beads having a diameter of several micrometers, or a preparation in which a lipid is bound to the peptide. In another aspect of the present invention, the peptides of the present invention may also be administered in the form of a pharmaceutically acceptable salt. Preferred examples of salts include salts with alkali metals (such as lithium, potassium, sodium, etc.), salts with alkaline earth metals (such as calcium, magnesium, etc.), salts with other metals (such as copper, iron, zinc, manganese, etc.), salts with organic bases, salts with amines, salts with organic acids (such as acetic acid, formic acid, propionic acid, fumaric acid, maleic acid, succinic acid, tartaric acid, citric acid, malic acid, oxalic acid, benzoic acid, methanesulfonic acid, etc.), and salts with inorganic acids (such as hydrochloric acid, phosphoric acid, hydrobromic acid, sulfuric acid, nitric acid, etc.). Accordingly, pharmaceutical compositions containing pharmaceutically acceptable salts of the peptides of the present invention are also encompassed by the present invention. Also, "the peptides of the present invention" includes not only the free peptides but also their pharmaceutically acceptable salts. In some embodiments, the pharmaceutical compositions of the present invention may further comprise a component that stimulates CTLs. Lipids have been identified as substances that can stimulate CTLs in vivo against viral antigens. For example, palmitic acid residues can be attached to the ε-amino and α-amino groups of lysine residues and then linked to the peptides of the present invention. The lipid-added peptides can then be administered directly in the form of micelles or particles, incorporated into liposomes for administration, or emulsified in adjuvants for administration. As another example of lipid stimulation of the CTL response, when covalently bound to an appropriate peptide, CTLs can be stimulated using Escherichia coli (E. coli) lipoproteins such as tripalmitoyl-S-glyceryl cysteinyl-serinyl-serine (P3CSS) (see, for example, Deres et al., Nature 1989, 342: 561-4). Examples of the method of administering the peptide or pharmaceutical composition of the present invention include, but are not limited to, oral, intradermal, subcutaneous, intramuscular, intraosseous, peritoneal, and intravenous injections, as well as systemic administration or local administration near the target site. Preferred methods of administration include subcutaneous injection near lymph nodes such as the axilla or cervical region. Administration can be carried out by single administration or boosted by multiple administrations. The peptide of the present invention can be administered to a subject in a therapeutically or pharmaceutically effective amount for treating coronavirus infection or in a therapeutically or pharmaceutically effective amount for inducing immunity (more specifically, CTL) against coronavirus-infected cells. The dosage of the peptide of the present invention can be appropriately adjusted according to the disease for therapeutic or prophylactic purposes, the age, weight, and administration method of the patient, etc., and for each peptide of the present invention, it is usually 0.001 mg to 1000 mg, for example 0.01 mg to 100 mg, for example 0.1 mg to 30 mg, for example 0.1 mg to 10 mg, and can be, for example, 0.5 mg to 5 mg. Also, the administration interval can be once every few days to several months, and for example, it can be administered at intervals of once a week. Those skilled in the art can appropriately select an appropriate dosage. In a preferred embodiment, the pharmaceutical composition of the present invention comprises a therapeutically effective amount of the peptide of the present invention and a pharmaceutically or physiologically acceptable carrier. In another embodiment, the pharmaceutical composition of the present invention comprises a therapeutically effective amount of the peptide of the present invention, a pharmaceutically or physiologically acceptable carrier, and an adjuvant. The pharmaceutical composition of the present invention can contain the peptide of the present invention in an amount of 0.001 mg to 1000 mg, preferably 0.01 mg to 100 mg, more preferably 0.1 mg to 30 mg, still more preferably 0.1 mg to 10 mg, for example 0.5 mg to 5 mg. Further, when the pharmaceutical composition of the present invention is an injection, the peptide of the present invention can be contained at a concentration of 0.001 mg / ml to 1000 mg / ml, preferably 0.01 mg / ml to 100 mg / ml, more preferably 0.1 mg / ml to 30 mg / ml, still more preferably 0.1 mg / ml to 10 mg / ml, for example 0.5 mg / ml to 5 mg / ml. In this case, for example, 0.1 to 5 ml, preferably 0.5 ml to 2 ml of the pharmaceutical composition of the present invention can be administered to a subject by injection. On the other hand, when the pharmaceutical composition of the present invention contains an adjuvant, the adjuvant can be formulated in an amount effective for enhancing the immune response of the subject to the peptide. Alternatively, the present invention provides a method for any one or more of the purposes of treating, preventing, and suppressing the aggravation of coronavirus infection, which comprises administering a therapeutically effective amount of the peptide of the present invention or the pharmaceutical composition of the present invention to a subject. The peptide of the present invention is usually 0.001 mg to 1000 mg, for example 0.01 mg to 100 mg, for example 0.1 mg to 30 mg, for example 0.1 mg to 10 mg as described above, and can be administered to a subject in an amount of, for example, 0.5 mg to 5 mg in a single administration. In a preferred embodiment, the peptide of the present invention is administered to a subject together with an adjuvant. Further, the administration interval can be once every several days to several months, preferably once every several days to one month, and can be, for example, once a week or once every two weeks. On the other hand, in the method of the present invention, when an adjuvant is administered together with the peptide, the adjuvant can be administered in an amount effective for enhancing the immune response of the subject to the peptide. (2)A pharmaceutical composition comprising a polynucleotide as an active ingredient The pharmaceutical composition of the present invention may also contain a polynucleotide encoding the peptide of the present invention in an expressible form. As used herein, the phrase "in an expressible form" means that when the polynucleotide is introduced into a cell, the peptide of the present invention is expressed. In an exemplary embodiment, the sequence of the polynucleotide of the present invention contains regulatory elements necessary for the expression of the peptide of the present invention. The polynucleotide of the present invention can be provided with sequences necessary to achieve stable insertion into the genome of the target cell (for an explanation of homologous recombination cassette vectors, see, for example, Thomas KR & Capecchi MR, Cell 1987, 51: 503-12). See, for example, Wolff et al., Science 1990, 247: 1465-8; U.S. Patent Nos. 5,580,859; 5,589,466; 5,804,566; 5,739,118; 5,736,524; 5,679,647; and WO98 / 04720. Examples of DNA-based delivery techniques include "naked DNA", facilitated (bupivacaine, polymer, peptide-mediated) delivery, cationic lipid complexes, and particle-mediated ("gene gun") or pressure-mediated delivery (see, for example, U.S. Patent No. 5,922,687). The peptides of the present invention can also be expressed by a viral vector or a bacterial vector. Examples of expression vectors include attenuated viral hosts such as vaccinia virus or fowlpox virus. For example, vaccinia virus can be used as a vector for expressing the peptides of the present invention. When introduced into a host, the recombinant vaccinia virus expresses an immunogenic peptide, thereby inducing an immune response. Vaccinia vectors and methods useful in immunization protocols are described, for example, in U.S. Patent No. 4,722,848. Another vector is BCG (Bacillus Calmette-Guerin). BCG vectors are described in Stover et al., Nature 1991, 351: 456-60. A variety of other vectors useful for therapeutic administration or immunization are apparent, such as adenovirus vectors and adeno-associated virus vectors, retrovirus vectors, Salmonella typhi vectors, detoxified anthrax toxin vectors, etc. See, for example, Shata et al., Mol Med Today 2000, 6: 66-71; Shedlock et al., J Leukoc Biol 2000, 68: 793-806; Hipp et al., In Vivo 2000, 14: 571-85. Delivery of the polynucleotides of the present invention into a patient can be direct, in which case the patient can be directly exposed to a vector carrying the polynucleotides of the present invention. Or it can be indirect, in which case cells are first transformed in vitro with a vector carrying the polynucleotides of the present invention and then the cells are transplanted into the patient. These two approaches are known as in vivo and ex vivo gene therapy, respectively. For a general review of the methods of gene therapy, see Goldspiel et al., Clinical Pharmacy 1993, 12: 488-505; Wu and Wu, Biotherapy 1991, 3: 87-95; Tolstoshev, Ann Rev Pharmacol Toxicol 1993, 33: 573-96; Mulligan, Science 1993, 260: 926-32; Morgan & Anderson, Ann Rev Biochem 1993, 62: 191-217; Trends in Biotechnology 1993, 11(5): 155-215. Methods generally known in the field of recombinant DNA technology that can also be used in the present invention are described in Ausubel et al., Current Protocols in Molecular Biology, John Wiley & Sons, NY, 1993; and Krieger, Gene Transfer and Expression, A Laboratory Manual, Stockton Press, NY, 1990. The administration method may be oral, intradermal, subcutaneous, intravenous injection, etc., and systemic administration or local administration near the target site is used. Administration can be carried out by single administration or boosted by multiple administrations. The polynucleotide of the present invention can be administered to a subject in a therapeutically or pharmaceutically effective amount for treating coronavirus infection or in a therapeutically or pharmaceutically effective amount for inducing immunity (more specifically CTL) against coronavirus-infected cells. The dose of the polynucleotide in a suitable carrier, or the dose of the polynucleotide in cells transformed with the polynucleotide encoding the peptide of the present invention, can be appropriately adjusted according to the disease to be treated, the age, weight, administration method, etc. of the patient, and this can usually be 0.001 mg to 1000 mg, for example 0.01 mg to 100 mg, for example, 0.1 mg to 30 mg, for example 0.1 mg to 10 mg, for example 0.5 mg to 5 mg. The administration interval can be once every few days to once every few months, for example, it can be administered at intervals of once a week.A person skilled in the art can appropriately select an appropriate dosage. X. Methods Using Peptides, Exosomes, APCs, and CTLs Using the peptides and polynucleotides of the present invention, APCs and CTLs can be induced. CTLs can also be induced using the exosomes and APCs of the present invention. The peptides, polynucleotides, exosomes, and APCs of the present invention can be used in combination with any other compound as long as their CTL-inducing ability is not inhibited. Therefore, CTLs of the present invention can be induced using a pharmaceutical composition containing any one of the peptides, polynucleotides, APCs, and exosomes of the present invention. Also, APCs of the present invention can be induced using a pharmaceutical composition containing the peptides or polynucleotides of the present invention. (1) Method for Inducing APCs The present invention provides a method for inducing APCs having CTL-inducing ability using the peptides or polynucleotides of the present invention. The method of the present invention includes the step of contacting APCs with the peptides of the present invention in vitro, ex vivo, or in vivo. For example, the method of contacting APCs with the peptides ex vivo may include the following steps: (a) The step of recovering APCs from a subject; and (b) The step of contacting the APCs of step (a) with the peptides of the present invention. The APCs are not limited to specific types of cells, and cells known to present proteinaceous antigens on their cell surfaces so as to be recognized by lymphocytes, such as DCs, Langerhans cells, macrophages, B cells, and activated T cells, can be used. Since DCs have the strongest CTL-inducing ability among APCs, DCs can preferably be used. Any peptide of the present invention can be used alone or in combination with other peptides of the present invention. Also, the peptides of the present invention and other CTL-inducing peptides (e.g., SARS-CoV-2, MERS-CoV and It can also be used in combination with other CTL-inducing peptides derived from viral structural or non-structural proteins of SARS-CoV. In certain embodiments, the method of the invention can further optionally include a step of recovering the APC after step (b). On the other hand, when the peptide of the invention is administered to a subject, the APC contacts the peptide in vivo, and as a result, APCs with high CTL-inducing ability are induced in the body of the subject. Thus, the method of the invention can include the step of administering the peptide of the invention to a subject. Similarly, when the polynucleotide of the invention is administered to a subject in an expressible form, the peptide of the invention is expressed in vivo, which contacts the APC in vivo, and as a result, APCs with high CTL-inducing ability are induced in the body of the subject. Thus, the invention can also include the step of administering the polynucleotide of the invention to a subject. The invention can also include the step of introducing the polynucleotide of the invention into an APC in order to induce an APC with CTL-inducing ability. For example, the method can include the following steps: (a) recovering APCs from a subject; and (b) introducing the polynucleotide encoding the peptide of the invention into the APCs of step (a). Step (b) can be performed as described above in the chapter "VI. Antigen-Presenting Cells (APCs)". Thus, in one aspect, the invention provides a method for inducing an APC with CTL-inducing ability, comprising the following step (a) or (b): (a) contacting an APC with the peptide of the invention; (b) introducing the polynucleotide encoding the peptide of the invention into the APC. Further, the invention provides a method for preparing an APC with CTL-inducing ability, comprising the following step (a) or (b): (a) contacting an APC with the peptide of the invention; (b) introducing the polynucleotide encoding the peptide of the invention into the APC. The above method can be carried out either in vitro, ex vivo, or in vivo, but it is preferably carried out in vitro or ex vivo. The APC used in the above method may be derived from the subject to whom the administration of the induced APC is planned, or it may be derived from a different subject. In one embodiment, the method of the present invention can further include a step of additionally recovering APC after step (b). When using APC derived from a subject (donor) different from the subject for whom administration is planned, the HLA types of the recipient and the donor need to be the same. In the method of the present invention, when using a peptide having an amino acid sequence selected from SEQ ID NOs: 1, 2, 3, 4, 5, 7, 9, 10, 11, 12, 13, 14, and 15 as the peptide of the present invention or a modified peptide thereof, the HLA types of the recipient and the donor are both HLA-A02 (more preferably HLA-A * 02:01 or HLA-A * 02:06). Alternatively, the APC used in the above method is preferably an APC expressing HLA-A02 (more preferably HLA-A * 02:01 or HLA-A * 02:06). When using a peptide having an amino acid sequence selected from SEQ ID NOs: 3 and 11 as the peptide of the present invention or a modified peptide thereof, the HLA types of the recipient and the donor are both preferably HLA-A24 (more preferably HLA-A * 24:02). Alternatively, the APC used in the above method is preferably an APC expressing HLA-A24 (more preferably HLA-A * 24:02). APC can be prepared from PBMC separated from blood collected from a donor by density centrifugation or the like, and then using a known method from the PBMC. In another aspect, the present invention also provides a pharmaceutical composition for inducing APC having CTL-inducing ability, comprising the peptide of the present invention or a polynucleotide encoding the peptide. Alternatively, the present invention further provides the use of the peptide of the present invention or a polynucleotide encoding the peptide in the manufacture of a pharmaceutical composition for inducing APCs having CTL-inducing ability. Alternatively, the present invention further provides the peptide of the present invention or a polynucleotide encoding the peptide for use in inducing APCs having CTL-inducing ability. Alternatively, the present invention further provides a method or process for manufacturing a pharmaceutical composition for inducing APCs, the method or process comprising formulating the peptide of the present invention or a polynucleotide encoding the peptide with a pharmaceutically or physiologically acceptable carrier. In another aspect, the present invention also provides a method or process for manufacturing a pharmaceutical composition for inducing APCs having CTL-inducing ability, the method or process comprising mixing the peptide of the present invention or a polynucleotide encoding the peptide with a pharmaceutically or physiologically acceptable carrier. The APCs induced by the method of the present invention can induce CTLs specific for coronavirus proteins (i.e., the CTLs of the present invention). (2) Method for inducing CTLs The present invention also provides a method for inducing CTLs using the peptide, polynucleotide, exosome, or APC of the present invention. When the peptide, polynucleotide, exosome, or APC of the present invention is administered to a subject, CTLs are induced in the subject's body, and the intensity of the immune response targeting coronavirus-infected cells is enhanced. Therefore, the method of the present invention may include the step of administering the peptide, polynucleotide, APC, or exosome of the present invention to a subject. Alternatively, CTLs can also be induced by using them in vitro or ex vivo. For example, the method of the present invention may include the following steps: (a) The step of recovering APCs from a subject, (b) The step of contacting the APCs of step (a) with the peptide of the present invention, and (c) Step of co-culturing the APC of step (b) with CD8-positive T cells. The induced CTL may then be returned to the subject. In the above step (c), the APC co-cultured with CD8-positive T cells can also be prepared by introducing a polynucleotide encoding the peptide of the present invention into the APC, as described above in the chapter "VI. Antigen-presenting cells (APC)". However, the APC used in the method of the present invention is not limited to this, and any APC that presents a complex of an HLA antigen and the peptide of the present invention on its surface can be used. In the method of the present invention, instead of such an APC, exosomes that present a complex of an HLA antigen and the peptide of the present invention on their surface can also be used. That is, the method of the present invention may include a step of co-culturing with exosomes that present a complex of an HLA antigen and the peptide of the present invention on their surface. Such exosomes can be prepared by the method described above in the chapter "V. Exosomes". Furthermore, CTL can also be induced by introducing a vector containing a polynucleotide encoding each subunit of a TCR that can bind to the peptide of the present invention presented by an HLA antigen on the cell surface into CD8-positive T cells. Such transduction can be performed as described above in the chapter "VIII. T cell receptor (TCR)". Therefore, in one aspect, the present invention provides a method for inducing CTL, comprising a step selected from the following: (a) Step of co-culturing CD8-positive T cells with an APC that presents a complex of an HLA antigen and the peptide of the present invention on its surface; (b) Step of co-culturing CD8-positive T cells with exosomes that present a complex of an HLA antigen and the peptide of the present invention on their surface; and (c) Step of introducing a vector containing a polynucleotide encoding each subunit of a TCR that can bind to the peptide of the present invention presented by an HLA antigen on the cell surface into CD8-positive T cells. The above method can be performed either in vitro, ex vivo, or in vivo, but it is preferably performed in vitro or ex vivo. When performed in vitro or ex vivo, in certain embodiments, the method of the present invention can include a step of recovering CTL induced after any step. The APC or exosome, and CD8-positive T cell used in the above method may be derived from the subject to whom administration of the induced CTL is planned, or may be derived from a different subject. When using an APC or exosome, and CD8-positive T cell derived from a subject (donor) different from the subject for whom administration is planned, the HLA types of the recipient and the donor need to be the same. For example, when using a peptide having an amino acid sequence selected from SEQ ID NOs: 1, 2, 3, 4, 5, 7, 9, 10, 11, 12, 13, 14, and 15 or a modified peptide thereof as the peptide of the present invention, the HLA types of the recipient and the donor are both HLA-A02 (more preferably HLA-A * 02:01 or HLA-A * 02:06). Alternatively, the APC or exosome used in the above method is preferably an APC or exosome that presents a complex of HLA-A02 (more preferably HLA-A * 02:01 or HLA-A * 02:06) and the peptide of the present invention (a peptide having an amino acid sequence selected from SEQ ID NOs: 1, 2, 3, 4, 5, 7, 9, 10, 11, 12, 13, 14, and 15 or a modified peptide thereof) on its surface. In this case, the induced CTL exhibits specific cytotoxic activity against cells presenting a complex of HLA-A02 and the peptide of the present invention (e.g., HLA-A02-positive cells infected with coronavirus). When using a peptide having an amino acid sequence selected from SEQ ID NOs: 3 and 11 or a modified peptide thereof as the peptide of the present invention, the HLA types of the recipient and the donor are both HLA-A24 (more preferably HLA-A *It is preferably (24:02). Alternatively, the APC or exosome used in the above method is an APC or exosome that presents a complex of HLA-A24 (more preferably HLA-A * 24:02) and the peptide of the present invention (a peptide having an amino acid sequence selected from SEQ ID NOs: 3 and 11 or a modified peptide thereof) on its own surface. In this case, the induced CTL exhibits specific cytotoxic activity against cells presenting a complex of HLA-A24 and the peptide of the present invention (for example, HLA-A24-positive cells infected with coronavirus). In another aspect, the present invention also provides a composition or pharmaceutical composition for inducing CTL, comprising at least one active ingredient selected from the following: (a) The peptide of the present invention; (b) A polynucleotide encoding the peptide of the present invention in an expressible form; (c) An APC presenting the peptide of the present invention on its own surface; and (d) An exosome presenting the peptide of the present invention on its own surface. In another aspect, the present invention also provides the use of an active ingredient selected from the following in the manufacture of a composition or pharmaceutical composition for inducing CTL: (a) The peptide of the present invention; (b) A polynucleotide encoding the peptide of the present invention in an expressible form; (c) An APC presenting the peptide of the present invention on its own surface; and (d) An exosome presenting the peptide of the present invention on its own surface. Alternatively, the present invention further provides an active ingredient selected from the following for use in the induction of CTL: (a) The peptide of the present invention; (b) A polynucleotide encoding the peptide of the present invention in an expressible form; (c) An APC presenting the peptide of the present invention on its own surface; and (d) An exosome presenting the peptide of the present invention on its own surface. Alternatively, the present invention further provides a method or process for manufacturing a composition or a pharmaceutical composition for inducing CTL, the method or process including the step of formulating an active ingredient selected from the following and a pharmaceutically or physiologically acceptable carrier: (a) the peptide of the present invention; (b) a polynucleotide encoding the peptide of the present invention in an expressible form; (c) an APC presenting the peptide of the present invention on its surface; and (d) an exosome presenting the peptide of the present invention on its surface. In another aspect, the present invention also provides a method or process for manufacturing a composition or a pharmaceutical composition for inducing CTL, the method or process including the step of mixing an active ingredient selected from the following with a pharmaceutically or physiologically acceptable carrier: (a) the peptide of the present invention; (b) a polynucleotide encoding the peptide of the present invention in an expressible form; (c) an APC presenting the peptide of the present invention on its surface; and (d) an exosome presenting the peptide of the present invention on its surface. XI. Method for inducing an immune response Furthermore, the present invention provides a method for inducing an immune response against a coronavirus infection. The coronaviruses include, but are not limited to, SARS-CoV-2, MERS-CoV, and SARS-CoV. Also, the coronavirus-infected cells preferably express HLA-A24 or HLA-A02. The present invention also provides a method for inducing an immune response against coronavirus-infected cells. The peptides of the present invention are derived from the structural or non-structural proteins of SARS-CoV-2 and are also amino acid sequences commonly found in SARS-CoV proteins and MERS-CoV proteins. Therefore, when an immune response against coronavirus-infected cells is induced, as a result, the growth of the virus in the coronavirus-infected cells is inhibited. Accordingly, the present invention also provides a method for inhibiting the growth of the virus in coronavirus-infected cells. The method of the present invention is particularly suitable for inhibiting the growth of coronavirus in coronavirus-infected cells expressing HLA-A24 or HLA-A02. The method of the present invention may include the step of administering a composition comprising any of the peptides of the present invention or polynucleotides encoding them. The method of the present invention also contemplates the administration of exosomes or APCs presenting any of the peptides of the present invention. For details, refer to the section "IX. Pharmaceutical Compositions", particularly the part describing the use of the pharmaceutical compositions of the present invention as vaccines. In addition, exosomes and APCs that can be used in the method of the present invention to induce an immune response are described in detail in the above-mentioned "V. Exosomes", "VI. Antigen-Presenting Cells (APCs)", and subsections (1) and (2) of "X. Methods Using Peptides, Exosomes, APCs, and CTLs". In another aspect, the present invention also provides a pharmaceutical composition or vaccine for inducing an immune response against coronavirus infection, the pharmaceutical composition or vaccine comprising an active ingredient selected from the following: (a) the peptides of the present invention; (b) a polynucleotide encoding the peptides of the present invention in an expressible form; (c) an APC presenting the peptides of the present invention on its surface; (d) exosomes presenting the peptides of the present invention on their surface; and (e) the CTLs of the present invention. Alternatively, the present invention further provides a pharmaceutical composition or vaccine for inducing an immune response against coronavirus-infected cells, the pharmaceutical composition or vaccine comprising an active ingredient selected from the following: (a) The peptide of the present invention; (b) A polynucleotide encoding the peptide of the present invention in an expressible form; (c) An APC presenting the peptide of the present invention on its surface; (d) An exosome presenting the peptide of the present invention on its surface; and (e) The CTL of the present invention. Alternatively, the present invention further provides a pharmaceutical composition or vaccine for inhibiting the growth of coronavirus in coronavirus-infected cells, the pharmaceutical composition or vaccine comprising an active ingredient selected from the following: (a) The peptide of the present invention; (b) A polynucleotide encoding the peptide of the present invention in an expressible form; (c) An APC presenting the peptide of the present invention on its surface; (d) An exosome presenting the peptide of the present invention on its surface; and (e) The CTL of the present invention. In another aspect, the present invention also provides the use of an active ingredient selected from the following in the manufacture of a pharmaceutical composition or vaccine for inducing an immune response against coronavirus infection: (a) The peptide of the present invention; (b) A polynucleotide encoding the peptide of the present invention in an expressible form; (c) An APC presenting the peptide of the present invention on its surface; (d) An exosome presenting the peptide of the present invention on its surface; and (e) The CTL of the present invention. Alternatively, the present invention further provides the use of an active ingredient selected from the following in the manufacture of a pharmaceutical composition or vaccine for inducing an immune response against coronavirus-infected cells: (a) The peptide of the present invention; (b) A polynucleotide encoding the peptide of the present invention in an expressible form; (c) An APC presenting the peptide of the present invention on its surface; (d) An exosome presenting the peptide of the present invention on its surface; and (e) The CTL of the present invention. Alternatively, the present invention further provides the use of an active ingredient selected from the following in the manufacture of a pharmaceutical composition or a vaccine for inhibiting the growth of a coronavirus in coronavirus-infected cells: (a) The peptide of the present invention; (b) A polynucleotide encoding the peptide of the present invention in an expressible form; (c) An APC presenting the peptide of the present invention on its surface; (d) An exosome presenting the peptide of the present invention on its surface; and (e) The CTL of the present invention. The present invention also provides a method or process for manufacturing a pharmaceutical composition for inducing an immune response against coronavirus infection, which may include the step of mixing or formulating the peptide of the present invention with a pharmaceutically acceptable carrier. Alternatively, the present invention provides a method for inhibiting the growth of a coronavirus in coronavirus-infected cells or a method for inducing an immune response against coronavirus infection, which includes the step of administering to a subject a vaccine or a pharmaceutical composition containing an active ingredient selected from the following: (a) The peptide of the present invention; (b) A polynucleotide encoding the peptide of the present invention in an expressible form; (c) An APC presenting the peptide of the present invention on its surface; (d) An exosome presenting the peptide of the present invention on its surface; and (e) The CTL of the present invention. In the context of the present invention, coronavirus infections can be treated by administering the peptides, polynucleotides, APCs, exosomes and / or CTLs of the present invention. Alternatively, an immune response against coronavirus infection can be induced by administering the peptides, polynucleotides, APCs, exosomes and / or CTLs of the present invention. Examples of such coronaviruses include, but are not limited to, SARS-CoV-2, MERS-CoV and SARS-CoV. In addition, an immune response against coronavirus-infected cells can be induced by administering the peptides, polynucleotides, APCs, exosomes and / or CTLs of the present invention. Therefore, it is preferable to confirm whether the subject to be treated is infected with a coronavirus before administering a vaccine or pharmaceutical composition containing the above active ingredients. Thus, in one aspect, the present invention provides a method of treating coronavirus infection in a patient in need thereof, such method comprising the following steps: i) measuring the expression level of the SARS-CoV-2 gene or the protein encoded thereby in a biological sample taken from a subject infected with a coronavirus; ii) identifying a subject infected with a coronavirus based on the SARS-CoV-2 gene or the protein expression level encoded thereby measured in i); and iii) administering to the subject infected with a coronavirus at least one active ingredient selected from the group consisting of (a)-(e) above. Alternatively, the present invention also provides a vaccine or pharmaceutical composition comprising at least one active ingredient selected from the group consisting of (a)-(e) above for administration to a subject infected with a coronavirus. The present invention further provides a method of identifying or selecting a subject to be treated with at least one active ingredient selected from the group consisting of (a)-(e) above, such method comprising the following steps: i) Measuring the expression level of the SARS-CoV-2 gene or the protein encoded thereby in a biological sample collected from a subject infected with the coronavirus; ii) Identifying a subject having coronavirus-infected cells expressing the SARS-CoV-2 gene or the protein encoded thereby based on the expression level of the SARS-CoV-2 gene or the protein encoded thereby measured in i); and iii) Identifying or selecting the subject identified in ii) as a subject who can be treated with at least one active ingredient selected from the group consisting of the above (a) to (e). In the above method, the biological sample collected from the subject for measuring the expression level of the SARS-CoV-2 gene or the protein encoded thereby is not particularly limited. For example, a tissue sample containing coronavirus-infected cells collected by biopsy or the like can be preferably used. Alternatively, the detection of coronavirus RNA in throat swabs or saliva is generally performed in the identification of coronavirus-infected individuals. Therefore, in the present invention, the coronavirus gene includes the genomic RNA of the coronavirus or the mRNA transcribed therefrom. The expression level of the SARS-CoV-2 gene or the protein encoded thereby in the biological sample can be measured by known methods. For example, methods for detecting the transcription product of the SARS-CoV-2 gene by a probe or PCR method (e.g., cDNA microarray method, Northern blot method, RT-PCR method, etc.), methods for detecting the translation product of the SARS-CoV-2 gene by an antibody or the like (e.g., Western blot method, immunostaining method, immunochromatography method, etc.) can be used. Further, the biological sample may be a blood sample. In this case, the blood level of the antibody against the SARS-CoV-2 protein may be measured, and the expression level of the SARS-CoV-2 protein may be evaluated based on the blood level. The measurement of the blood level of the antibody against the SARS-CoV-2 protein can be performed using known methods. For example, enzyme immunoassay (EIA), enzyme-linked immunosorbent assay (ELISA), and radioimmunoassay (RIA) using the SARS-CoV-2 protein or the peptide of the present invention as an antigen can be used. In addition, by detecting CTLs specific to the peptide of the present invention, the expression level of the SARS-CoV-2 protein in a subject may be evaluated. Measurement of the CTL level specific to the peptide of the present invention can be performed, for example, by separating PBMCs from blood collected from a subject and measuring the cytotoxic activity against target cells pulsed with the peptide of the present invention. Measurement of the cytotoxic activity can be performed, for example, by measuring the amount of interferon-γ released. In addition, the complex of the peptide of the present invention described below and HLA can also be used for measuring the CTL level. Note that the determination of whether the coronavirus-infected cells of a subject express the SARS-CoV-2 protein may be made by comparison with the measurement results in the same type of biological material collected from a subject not infected with the coronavirus. That is, compared with the level of the measurement object (normal control level) in the same type of biological material collected from a subject not infected with the coronavirus, if the level in the biological sample collected from a subject infected with the coronavirus is elevated, it can be determined that the cells of the subject infected with the coronavirus express the SARS-CoV-2 protein. In a preferred embodiment, it is preferable to confirm the HLA type of the subject before administering at least one active ingredient selected from the group consisting of the above (a) to (e). For example, as the administration target of the active ingredient related to the peptide having an amino acid sequence selected from SEQ ID NOs: 1, 2, 3, 4, 5, 7, 9, 10, 11, 12, 13, 14, and 15, it is preferable to select a subject positive for HLA-A02. As the administration target of the active ingredient related to the peptide having an amino acid sequence selected from SEQ ID NOs: 3 and 11, it is preferable to select a subject positive for HLA-A24. Methods for so-called HLA typing for determining the HLA haplotype are well known to those skilled in the art. Alternatively, a lymphocyte cytotoxicity test (LCT method) for determining the HLA type based on the reactivity between an antibody specific to each HLA and the HLA antigen on lymphocytes is also known. The present invention also provides a complex of the peptide of the present invention and HLA. The complex of the present invention may be a monomer or a multimer. When the complex of the present invention is a multimer, the polymerization number is not particularly limited, and it can be a multimer with any polymerization number. Examples include, but are not limited to, tetramers, pentamers, hexamers, etc. Also, dextramers (WO2002 / 072631), streptamers (Knabel M et al., Nat Med. 2002 Jun;8(6):631-7.) are also included in the multimers of the present invention. The complex of the peptide of the present invention and HLA can be prepared according to known methods (for example, Altman JD et al., Science.1996,274(5284):94-6, WO2002 / 072631, WO2009 / 003492, Knabel M et al., Nat Med. 2002 Jun;8(6):631-7., etc.). The complex of the present invention can be used, for example, for quantifying CTL specific to the peptide of the present invention. For example, a blood sample is collected from a subject administered with the pharmaceutical composition of the present invention, CD4-negative cells are prepared after separating PBMC, and the complex of the present invention conjugated with a fluorescent dye is brought into contact with the CD4-negative cells. Then, by analyzing with flow cytometry, the ratio of CTL specific to the peptide of the present invention can be measured. For example, by measuring CTL specific to the peptide of the present invention before, during, and / or after administration of the pharmaceutical composition of the present invention, the immune response induction effect by the pharmaceutical composition of the present invention can be monitored. XII. Antibodies The present invention further provides an antibody that binds to the peptide of the present invention. Preferred antibodies specifically bind to the peptide of the present invention and do not bind (or bind weakly) to those that are not the peptide of the present invention. The binding specificity of the antibody can be confirmed by an inhibition assay. That is, when the binding between the antibody to be analyzed and a polypeptide (SEQ ID NOs: 17-26) consisting of the amino acid sequence of each protein encoded by the genomic sequence of full-length SARS-CoV-2 is inhibited in the presence of the peptide of the present invention, it is shown that this antibody specifically binds to the peptide of the present invention. Antibodies against the peptide of the present invention can be used in assays for the diagnosis and prognosis of diseases, as well as in the selection of administration targets and monitoring of the pharmaceutical compositions of the present invention. The present invention also provides various immunoassay methods for detecting and / or quantifying the peptide of the present invention or a fragment thereof. Such immunoassay methods are carried out within the scope of various immunoassay formats well known in the art, including but not limited to radioimmunoassay, immunochromatography, enzyme-linked immunosorbent assay (ELISA), enzyme-linked immunofluorescence assay (ELIFA), etc. The antibody of the present invention can be used in an immunoimaging method capable of detecting coronavirus-infected cells, examples of which include, but are not limited to, a radioisotope imaging method using the labeled antibody of the present invention. Such assay methods are clinically used in the detection, monitoring, and prognosis of coronavirus-infected cells, and examples of such coronaviruses causing such coronavirus infections include, but are not limited to, SARS-CoV-2, MERS-CoV, SARS-CoV, etc. The antibody of the present invention can be used in any form, such as a monoclonal antibody or a polyclonal antibody, and can further include antiserum obtained by immunizing an animal such as a rabbit with the peptide of the present invention, all classes of polyclonal antibodies and monoclonal antibodies, human antibodies, as well as chimeric antibodies and humanized antibodies produced by genetic recombination. The peptide or fragment thereof of the present invention used as an antigen for obtaining an antibody can be obtained by chemical synthesis or by genetic engineering techniques based on the amino acid sequences disclosed herein. The peptide used as an immunizing antigen may be the peptide of the present invention or a fragment of the peptide of the present invention. Further, in order to enhance immunogenicity, the peptide may be conjugated or linked to a carrier. As a carrier, keyhole limpet hemocyanin (KLH) is well known. Methods for conjugating KLH and a peptide are also well known in the art. Any mammal can be immunized with the antigen, but when producing monoclonal antibodies, it is preferable to take into account the compatibility with the parent cells used for cell fusion. Generally, animals of the order Rodentia, Lagomorpha, or Primate can be used. Examples of animals of the order Rodentia include mice, rats, and hamsters. Examples of animals of the order Lagomorpha include rabbits. Examples of animals of the order Primate include monkeys of the suborder Catarrhini (Old World monkeys) such as Macaca fascicularis, rhesus monkeys, baboons, and chimpanzees. Methods for immunizing animals with an antigen are known in the art. Intraperitoneal injection or subcutaneous injection of the antigen is a standard method for immunizing mammals. More specifically, the antigen is diluted and suspended in an appropriate amount of phosphate-buffered saline (PBS), physiological saline, etc. If necessary, the antigen suspension can be mixed with an appropriate amount of a standard adjuvant such as Freund's complete adjuvant, emulsified, and then administered to the mammal. Thereafter, it is preferable to administer the antigen mixed with an appropriate amount of Freund's incomplete adjuvant several times every 4 to 21 days. An appropriate carrier may be used for immunization. After immunization as described above, the serum can be examined by standard methods for an increase in the amount of the desired antibody. The polyclonal antibody against the peptide of the present invention can be prepared by collecting blood from a mammal in which an increase in the desired antibody level in the serum has been confirmed after immunization, and separating the serum from the blood by any conventional method. The polyclonal antibody may be serum containing the polyclonal antibody, or a fraction containing the polyclonal antibody may be isolated from the serum. Immunoglobulin G or M can be prepared by further purifying this fraction using a protein A or protein G column after using an affinity column to which the peptide of the present invention is bound, from a fraction that recognizes only the peptide of the present invention. To prepare a monoclonal antibody, after confirming an increase in the desired antibody level in the serum after immunization, immune cells are collected from a mammal and subjected to cell fusion. The immune cells used for cell fusion can preferably be obtained from the spleen. As the other parent cell to be fused with the above immune cells, for example, mammalian myeloma cells, and more preferably myeloma cells that have acquired characteristics for the selection of fused cells by drugs can be used. The above immune cells and myeloma cells can be fused according to a known method, for example, the method of Milstein et al. (Galfre and Milstein, Methods Enzymol 73: 3-46 (1981)). The hybridomas obtained by cell fusion can be selected by culturing them in a standard selection medium such as HAT medium (a medium containing hypoxanthine, aminopterin, and thymidine). Cell culture typically continues for a period (for example, several days to several weeks) sufficient for all other cells (non-fused cells) except the desired hybridomas to die in the HAT medium. Thereafter, standard limiting dilution can be performed to screen and clone hybridoma cells that produce the desired antibody. In addition to the above method of immunizing a non-human animal with an antigen to prepare a hybridoma, human lymphocytes such as lymphocytes infected with Epstein-Barr virus can also be immunized in vitro with a peptide, a cell expressing the peptide, or a lysate thereof. Subsequently, the immunized lymphocytes can be fused with an immortalizable human-derived myeloma cell such as U266 to obtain a hybridoma that produces a desired human antibody capable of binding to the peptide (Japanese Patent Laid-Open No. 63-17688). Subsequently, the obtained hybridoma is transplanted into the abdominal cavity of a mouse, and ascites is extracted. The obtained monoclonal antibody can be purified, for example, by ammonium sulfate precipitation, a protein A or protein G column, DEAE ion exchange chromatography, or an affinity column to which the peptide of the present invention is bound. Alternatively, immune cells that produce antibodies, such as immunized lymphocytes, can be immortalized by an oncogene and used for the preparation of monoclonal antibodies. The monoclonal antibody thus obtained can also be prepared recombinantly using genetic engineering techniques (see, for example, Borrebaeck and Larrick, Therapeutic Monoclonal Antibodies, published in the United Kingdom by MacMillan Publishers LTD (1990)). For example, DNA encoding an antibody can be cloned from an immune cell such as a hybridoma or immunized lymphocyte that produces the antibody, inserted into an appropriate vector, and then introduced into a host cell to prepare a recombinant antibody. The present invention also provides a recombinant antibody prepared as described above. Furthermore, the antibody of the present invention may be an antibody fragment or a modified antibody as long as it binds to the peptide of the present invention. For example, antibody fragments include Fab, F(ab')[ 2, Fv, or a single-chain Fv (scFv) in which the Fv fragment derived from the H chain and L chain is linked by an appropriate linker (Huston et al., Proc Natl Acad Sci USA 85: 5879-83 (1988)). More specifically, the antibody fragment can be prepared by treating the antibody with an enzyme such as papain or pepsin. Alternatively, a gene encoding the antibody fragment can be constructed, inserted into an expression vector, and expressed in an appropriate host cell (see, for example, Co et al., J Immunol 152: 2968-76 (1994); Better and Horwitz, Methods Enzymol 178: 476-96 (1989); Pluckthun and Skerra, Methods Enzymol 178: 497-515 (1989); Lamoyi, Methods Enzymol 121: 652-63 (1986); Rousseaux et al., Methods Enzymol 121: 663-9 (1986); Bird and Walker, Trends Biotechnol 9: 132-7 (1991)). Antibodies can be modified by conjugation with various molecules such as polyethylene glycol (PEG). The present invention provides such modified antibodies. Modified antibodies can be obtained by chemically modifying the antibodies. These modification methods are conventional in the art. Alternatively, the antibody of the present invention can be obtained as a chimeric antibody between a variable region derived from a non-human antibody and a constant region derived from a human antibody, or as a humanized antibody comprising a complementarity-determining region (CDR) derived from a non-human antibody and a framework region (FR) and a constant region derived from a human antibody. Such antibodies can be prepared according to known techniques. Humanization can be performed by replacing the corresponding sequence of a human antibody with the CDR sequence of a non-human antibody (see, for example, Verhoeyen et al., Science 239:1534-6 (1988)). Thus, such humanized antibodies are chimeric antibodies in which a human variable domain that is not substantially fully satisfied is replaced by the corresponding sequence from a non-human species. In addition to human framework and constant regions, a fully human antibody that also includes a human variable region can also be used. Such antibodies can be produced using various techniques known in the art. For example, in vitro methods include the use of recombinant libraries of human antibody fragments displayed on bacteriophage (see, for example, Hoogenboom & Winter, J. Mol. Biol. 227: 381 (1991)). Similarly, human antibodies can also be produced by introducing the human immunoglobulin locus into transgenic animals, such as mice, in which the endogenous immunoglobulin genes are partially or completely inactivated. This approach is described, for example, in U.S. Patent Nos. 6,150,584, 5,545,807; 5,545,806; 5,569,825; 5,625,126; 5,633,425; 5,661,016. The antibody obtained as described above may be purified until it becomes homogeneous. For example, the separation and purification of the antibody can be carried out according to separation and purification methods used for general proteins. For example, but not limited to these, the separation and isolation of the antibody can be achieved by appropriately selecting and combining the use of column chromatography such as affinity chromatography, filters, ultrafiltration, salting out, dialysis, SDS polyacrylamide gel electrophoresis, and isoelectric focusing (Antibodies: A Laboratory Manual. Ed Harlow and David Lane, Cold Spring Harbor Laboratory (1988)). Protein A columns and Protein G columns can be used as affinity columns. Exemplary Protein A columns to be used include, for example, Hyper D, POROS, and Sepharose F.F. (Pharmacia). Exemplary chromatography includes, in addition to affinity chromatography, for example, ion exchange chromatography, hydrophobic chromatography, gel filtration, reverse phase chromatography, adsorption chromatography, etc. (Strategies for Protein Purification and Characterization: A Laboratory Course Manual. Ed Daniel R. Marshak et al., Cold Spring Harbor Laboratory Press (1996)). Chromatography procedures can be carried out by liquid chromatography such as HPLC and FPLC. For example, the antigen-binding activity of the antibody of the present invention can be measured using absorbance measurement, enzyme-linked immunosorbent assay (ELISA), enzyme immunoassay (EIA), radioimmunoassay (RIA), and / or immunofluorescence method (IF). In the case of ELISA, the antibody of the present invention is immobilized on a plate, the peptide of the present invention is added to the plate, and then a sample containing a desired antibody such as a culture supernatant of antibody-producing cells or a purified antibody is added. Next, a secondary antibody that recognizes the primary antibody and is labeled with an enzyme such as alkaline phosphatase is added, and the plate is incubated. Subsequently, after washing, an enzyme substrate such as p-nitrophenyl phosphate is added to the plate, and the absorbance is measured to evaluate the antigen-binding activity of the sample. To evaluate the binding activity of the antibody, a peptide fragment such as a C-terminal or N-terminal fragment may be used as an antigen. BIAcore (Pharmacia) may also be used to evaluate the activity of the antibody of the present invention. By exposing the antibody of the present invention to a sample considered to contain the peptide of the present invention and detecting or measuring the immune complex formed by the antibody and the peptide, the peptide of the present invention can be detected or measured by the method as described above. For example, the antibody of the present invention can also be used to detect the peptide of the present invention present in a blood sample (e.g., serum sample) of a subject. Alternatively, conversely, the antibody of the present invention present in a blood sample (e.g., serum sample) of a subject can be detected using the peptide of the present invention. The results of measuring the peptide or the antibody of the present invention in a blood sample of a subject can be used for selecting an administration subject of the pharmaceutical composition of the present invention or monitoring the effect of the pharmaceutical composition of the present invention. XIII. Vectors and Host Cells The present invention also provides a vector containing a polynucleotide encoding the peptide of the present invention and a host cell into which the vector has been introduced. The vector of the present invention can be used to retain the polynucleotide of the present invention in a host cell, to express the peptide of the present invention in a host cell, or to administer the polynucleotide of the present invention for gene therapy. When Escherichia coli is the host cell and the vector is amplified in Escherichia coli (e.g., JM109, DH5α, HB101, or XL1-Blue) to produce a large quantity, the vector needs to have an "origin of replication" for amplification in Escherichia coli and a marker gene for selecting the transformed Escherichia coli (e.g., a drug resistance gene selected by a drug such as ampicillin, tetracycline, kanamycin, chloramphenicol, etc.). For example, M13-based vectors, pUC-based vectors, pBR322, pBluescript, pCR-Script, etc. can be used. In addition, pGEM-T, pDIRECT, and pT7 can also be used for cloning in the same manner as the above vectors. When the vector is used for the production of the peptide of the present invention, an expression vector can be used. For example, an expression vector for expression in Escherichia coli needs to have the above characteristics for amplification in Escherichia coli. When using Escherichia coli such as JM109, DH5α, HB101, or XL1-Blue as the host cell, the vector needs to have a promoter capable of efficiently expressing the desired gene in Escherichia coli, such as the lacZ promoter (Ward et al., Nature 341: 544-6 (1989); FASEB J 6: 2422-7 (1989)), the araB promoter (Better et al., Science 240: 1041-3 (1988)), the T7 promoter, etc. In this regard, for example, pGEX-5X-1 (Pharmacia), the "QIAexpress system" (Qiagen), pEGFP, and pET (in this case, the host is preferably BL21 expressing T7 RNA polymerase) can be used instead of the above vectors. Furthermore, the vector may contain a signal sequence for peptide secretion. An exemplary signal sequence for secreting the peptide into the periplasm of Escherichia coli is the pelB signal sequence (Lei et al., J Bacteriol 169: 4379 (1987)). Means for introducing the vector into the target host cell include, for example, the calcium chloride method and the electroporation method. In addition to Escherichia coli, for example, expression vectors derived from mammals (e.g., pcDNA3 (Invitrogen), and pEGF-BOS (Nucleic Acids Res 18(17): 5322 (1990)), pEF, pCDM8), expression vectors derived from insect cells (e.g., "Bac-to-BAC baculovirus expression system" (GIBCO BRL), pBacPAK8), expression vectors derived from plants (e.g., pMH1, pMH2), expression vectors derived from animal viruses (e.g., pHSV, pMV, pAdexLcw), expression vectors derived from retroviruses (e.g., pZIpneo), expression vectors derived from yeast (e.g., "Pichia expression kit" (Invitrogen), pNV11, SP-Q01), and expression vectors derived from Bacillus subtilis (e.g., pPL608, pKTH50) can be used for the production of the polypeptide of the present invention. In order to express a vector in animal cells such as CHO, COS, or NIH3T3 cells, the vector needs to have a promoter necessary for expression in such cells, for example, the SV40 promoter (Mulligan et al., Nature 277: 108 (1979)), the MMLV-LTR promoter, the EF1α promoter (Mizushima et al., Nucleic Acids Res 18: 5322 (1990)), the CMV promoter, etc., and preferably a marker gene for selecting transformants (e.g., a drug resistance gene selected by a drug (e.g., neomycin, G418)). Examples of known vectors having these characteristics include, for example, pMAM, pDR2, pBK-RSV, pBK-CMV, pOPRSV, and pOP13. XIV. Method for Detecting History of SARS-CoV-2 Infection Detection of Cellular Response due to SARS-CoV-2 Infection in a Subject Significant IFN-γ production was shown in T cells stimulated by specific peptides derived from SARS-CoV-2 proteins (SEQ ID NOs: 7, 10, 12). Therefore, peptide-specific CTL clones were established, TCR sequence analysis was performed, and the CDR3 amino acid sequences of the TCRs expressed by the SARS-CoV-2 protein-derived peptide-specific CTL clones were identified (Table 4). When a TCRα or TCRβ containing a CDR3 of the amino acid sequence as shown in Table 4, or a pair thereof, is detected in a subject, it means that a peptide-specific CTL response has been induced in the subject. Therefore, an increase in a specific pair of genes in a T cell population stimulated by a SARS-CoV-2 protein-derived peptide may be useful as a surrogate marker for detecting a CTL response in a subject after stimulation. If such a CTL response is confirmed, it means that the subject has been infected with SARS-CoV-2 in the past. In the context of the present invention, "peptide-specific CTL response" is understood to mean that the TCR formed between the α and β subunits specifically recognizes the complex formed between the peptide of the present invention and the HLA molecule. As discussed above, the CTL cell-inducing ability of the peptides defined by the specific sequences of the present invention can be maintained even after amino acid modification. Therefore, in addition to stimulation with specific peptides, even when T cells are derived from mutant peptides, as long as the TCR specifically recognizes such a complex formed by the original peptide, its antigen specificity is considered "peptide-specific". In a preferred embodiment, the present invention is a method for detecting a T cell response due to SARS-CoV-2 infection in a subject, comprising: (a) providing a sample obtained from the subject, wherein the sample contains T cells; (b) detecting the presence of SARS-CoV-2 protein-derived peptide-specific T cells induced by SARS-CoV-2 infection in the sample; and (c) when the presence of the T cells is shown in (b) using the T cell receptor (TCR) as an indicator, indicating the possibility of past infection with SARS-CoV-2 Provided is a method including, for example, by detecting either or both of an α subunit and a β subunit containing a CDR3 consisting of the amino acid sequence shown in Table 4, it is possible to clarify the possibility of having been infected with SARS-CoV-2 in the past. Specifically, for example, PBMCs are collected from the blood of a subject (HLA-A * 02:01 or HLA-A * 02:06 positive) who wants to examine their past SARS-CoV-2 infection history, and TCR repertoire analysis is performed. On the other hand, for example, for SARS-CoV-2 non-infected individuals (HLA-A * 02:01 or HLA-A * 02:06 positive) as a comparative control, similar repertoire analysis results are obtained for their PBMCs, and when more SARS-CoV-2 protein-derived peptide-specific T cells are detected compared to the comparative control, it is shown that the subject has a past SARS-CoV-2 infection history. As a comparative control, for example, human PBMCs before the reported infection of SARS-CoV-2 in humans can be used. Specifically, human PBMCs prepared from blood collected before December 2019 can be used as a comparative control, but it is not limited to this. In the present invention, any biological sample obtained from a subject can be used to detect a T cell response as long as the sample contains T cells. For example, for the purposes of the present invention, blood or a blood-derived sample can be used as a biological sample. In the present invention, a blood-derived sample contains a cell population containing T cells. Methods for obtaining a cell population containing T cells are well known to those skilled in the art. The T cell receptor (TCR) consists of V gene, D gene, J gene, and C gene. Due to the rearrangement of V genes and J genes, and further random insertions and deletions of bases between V-D-J genes (CDR3), it is considered that the TCR has a diversity of up to 10 to the 18th power. Therefore, there are T cells expressing various TCRs in the human body. Examining the diversity of TCRs in a certain T cell population (which TCRs are detected at what frequencies) is called TCR repertoire analysis. When performing TCR repertoire analysis, in order to amplify various TCR genes without bias by PCR, cDNA with an adapter attached to the 5' end is synthesized from RNA derived from a T cell population. Next-generation sequencing (NGS) is used to determine the base sequence of a large amount of DNA fragments (sequencing library) obtained using an adapter-specific forward primer and a TCR-α or TCR-β specific reverse primer. Next-generation sequencers are devices capable of determining the base sequences of millions of DNA fragments in parallel. In TCR repertoire analysis, it is necessary to determine long base sequences across the V, D, J, and C genes that make up the TCR. Therefore, among next-generation sequencers, MiSeq (Illumina), which is good at long-read analysis (determining base sequences of approximately 300 bp), is often used. By comprehensively analyzing the nucleotide sequence of the mRNA encoding the TCR contained in the sample (which essentially means analyzing the nucleotide sequence of the cDNA obtained by reverse transcribing the nucleotide sequence of the mRNA), the detection frequency of each CDR3 in the T cell population constituting the sample can be easily known. Examples of the nucleotide sequences of primers useful for determining the nucleotide sequence of CDR3 are shown below. Forward primer (adapter sequence common to TCR-α and TCR-β, SEQ ID NO: 44): 5'-GTCTCGTGGGCTCGGAGATGTGTATAAGAGACAGTATCAACGCAGAGTGGCCAT-3' Reverse primer (for TCR-α, SEQ ID NO:46): 5'-TCGTCGGCAGCGTCAGATGTGTATAAGAGACAGDBDHHCAGGGTCAGGGTTCTGGATA-3' Reverse primer (for TCR-β, SEQ ID NO:45): 5'-TCGTCGGCAGCGTCAGATGTGTATAAGAGACAGDVHDVTCTGATGGCTCAAACACAGC-3' That is, the present invention provides a method for detecting a T cell response, including the following steps: (a) Extracting gDNA from PBMCs derived from a subject, or synthesizing cDNA using RNA extracted from PBMCs as a template; (b) Decoding the TCRα gene sequence and the TCRβ gene sequence from the gDNA or cDNA, and determining the frequency of each amino acid sequence in the TCR; (c) When a SARS-CoV-2-derived peptide-reactive TCR is detected in each amino acid sequence of the TCR determined in (b), it indicates the presence of SARS-CoV-2-specific T cells induced by infection. In one aspect of the present invention, the detection frequency of the SARS-CoV-2-derived peptide-reactive TCR can be compared with a comparative control. For example, the TCR repertoire analysis results of PBMCs derived from SARS-CoV-2 non-infected individuals can be used as a comparative control. Therefore, when the detection frequency of the SARS-CoV-2-derived peptide-reactive TCR is detected more frequently compared to the comparison target, it indicates that a SARS-CoV-2-specific T cell response has been induced. Prior to the method of the present invention, the step of collecting peripheral blood mononuclear cells (PBMCs) from a subject can be included. By repeating a series of analyses over time, the change in the frequency of the SARS-CoV-2-derived peptide-reactive TCR can also be tracked. For example, after inoculation with the SARS-CoV-2-derived peptide of the present invention or after SARS-CoV-2 infection, the change in the frequency of the SARS-CoV-2-derived peptide-reactive TCR can be tracked to evaluate the enhancement effect of the immune response. Therefore, by the method for detecting a T cell response of the present invention, the induction result of the immune response in a subject administered with the peptide of the present invention can be known. That is, the present invention provides a method for detecting a T cell response, including the step of administering the peptide of the present invention to a subject and the step of detecting a T cell response in the subject after administration. Further, the present invention can additionally select a subject in whom a sufficient T cell response has not been detected and use it as a subject for booster vaccination with the peptide of the present invention. Aspects of the present invention based on the above description are exemplified below, but the present invention is not limited thereto. [1] A peptide having a cytotoxic T lymphocyte (CTL) - inducing ability and having less than 15 amino acids, comprising an amino acid sequence selected from the following group: (a) an amino acid sequence selected from the group consisting of SEQ ID NOs: 1, 2, 3, 4, 5, 7, 9, 10, 11, 12, 13, 14, and 15; and (b) an amino acid sequence in which one, two, or several amino acids are substituted, deleted, inserted, and / or added with respect to the amino acid sequence selected from the group consisting of SEQ ID NOs: 1, 2, 3, 4, 5, 7, 9, 10, 11, 12, 13, 14, and 15. [2] The peptide according to [1], having one or both of the following characteristics with respect to the amino acid sequence selected from the group consisting of SEQ ID NOs: 1, 2, 3, 4, 5, 7, 9, 10, 11, 12, 13, 14, and 15: (a) The second amino acid from the N - terminus is substituted with an amino acid selected from the group consisting of leucine and methionine; and (b) The C - terminal amino acid is substituted with an amino acid selected from the group consisting of valine and leucine. [3] The peptide according to [1], having one or both of the following characteristics with respect to the amino acid sequence selected from the group consisting of SEQ ID NOs: 3, 4, 7, 10, 11, 12, and 15: (a) The second amino acid from the N - terminus is substituted with an amino acid selected from the group consisting of valine and glutamine; and (b) The C - terminal amino acid is substituted with an amino acid selected from the group consisting of valine and leucine. [4] The peptide according to [1], having one or both of the following characteristics with respect to the amino acid sequence selected from the group consisting of SEQ ID NOs: 3 and 11: (a) The second amino acid from the N - terminus is substituted with an amino acid selected from the group consisting of phenylalanine, tyrosine, methionine, and tryptophan; and (b) The C-terminal amino acid is substituted with an amino acid selected from the group consisting of phenylalanine, leucine, isoleucine, tryptophan, or methionine. [5] The peptide according to [1], comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 1, 2, 3, 4, 5, 7, 9, 10, 11, 12, 13, 14, and 15. [6] A polynucleotide encoding the peptide according to any one of [1] to [5]. [7] A composition comprising a pharmaceutically acceptable carrier and at least one active ingredient selected from the group consisting of the following (a) to (e): (a) One or more peptides according to any one of [1] to [5]; (b) One or more polynucleotides encoding the peptide according to any one of [1] to [5] in an expressible form; (c) An antigen-presenting cell (APC) presenting a complex of a peptide according to any one of [1] to [5] and an HLA antigen on its own cell surface; (d) An exosome presenting a complex of a peptide according to any one of [1] to [5] and an HLA antigen on its own cell surface; and (e) A CTL targeting a peptide according to any one of [1] to [5]. [8] The composition according to [7], wherein the active ingredient is at least one active ingredient selected from the group consisting of the following (a) to (d), and the composition is for inducing CTL: (a) One or more peptides according to any one of [1] to [5]; (b) One or more polynucleotides encoding the peptide according to any one of [1] to [5] in an expressible form; (c) An antigen-presenting cell (APC) presenting a complex of a peptide according to any one of [1] to [5] and an HLA antigen on its own cell surface; and (d) An exosome presenting a complex of a peptide according to any one of [1] to [5] and an HLA antigen on its own cell surface. [9] The composition according to [7], which is a pharmaceutical composition.

[0010] The composition according to [9], which is a pharmaceutical composition for one or more uses selected from the group consisting of (i) the treatment of coronavirus infection, (ii) the prevention of coronavirus infection, and (iii) the suppression of the aggravation of coronavirus infection.

[0011] The composition according to [9], for inducing an immune response against coronavirus infection.

[0012] The composition according to

[0010] or

[0011] , wherein the coronavirus of coronavirus infection is selected from the group consisting of SARS-CoV-2, MERS-CoV, and SARS-CoV.

[0013] The composition according to any one of [7] to

[0012] , which is formulated for administration to a subject who is positive for HLA-A02 or HLA-A24.

[0014] A method for inducing an APC having CTL-inducing ability, comprising a step selected from the group consisting of the following (a) and (b): (a) contacting an APC with the peptide according to any one of [1] to [5] in vitro, ex vivo, or in vivo, and (b) introducing a polynucleotide encoding the peptide according to any one of [1] to [5] into the APC.

[0015] A method for inducing CTL, comprising a step selected from the group consisting of the following (a) to (c): (a) co-culturing CD8-positive T cells with an APC that presents a complex of an HLA antigen and the peptide according to any one of [1] to [5] on its own surface, (b) co-culturing CD8-positive T cells with exosomes that present a complex of an HLA antigen and the peptide according to any one of [1] to [5] on their own surface, and (c) introducing a polynucleotide encoding each subunit of a T cell receptor (TCR) that can bind to the peptide according to any one of [1] to [5] presented by an HLA antigen on the cell surface into CD8-positive T cells.

[0016] An APC that presents a complex of an HLA antigen and a peptide according to any one of [1] to [5] on its own surface.

[0017] The APC according to

[0016] , induced by the method according to

[0014] .

[0018] CTL targeting a peptide according to any one of [1] to [5].

[0019] The CTL according to

[0018] , induced by the method according to

[0015] .

[0020] A method for inducing an immune response against coronavirus infection, comprising the step of administering to a subject at least one active ingredient selected from the group consisting of the following (a) to (e): (a) One or more peptides according to any one of [1] to [5]; (b) One or more polynucleotides encoding a peptide according to any one of [1] to [5] in an expressible form; (c) An antigen-presenting cell (APC) that presents a complex of a peptide according to any one of [1] to [5] and an HLA antigen on its own cell surface; (d) An exosome that presents a complex of a peptide according to any one of [1] to [5] and an HLA antigen on its own cell surface; and (e) CTL targeting a peptide according to any one of [1] to [5].

[0021] A method for any one or more purposes selected from the treatment, prevention, and suppression of severe progression of coronavirus infection, comprising the step of administering to a subject at least one active ingredient selected from the group consisting of the following (a) to (e): (a) One or more peptides according to any one of [1] to [5]; (b) One or more polynucleotides encoding a peptide according to any one of [1] to [5] in an expressible form; (c) An antigen-presenting cell (APC) that presents a complex of a peptide according to any one of [1] to [5] and an HLA antigen on its own cell surface; (d)An exosome that presents a complex of a peptide according to any one of [1] to [5] and an HLA antigen on the surface of its own cells; and (e)A CTL that targets a peptide according to any one of [1] to [5].

[0022] An antibody that binds to a peptide according to any one of [1] to [5].

[0023] A method for screening a peptide having CTL-inducing ability, the method comprising the following steps: (a)For an original amino acid sequence consisting of an amino acid sequence selected from SEQ ID NOs: 1, 2, 3, 4, 5, 7, 9, 10, 11, 12, 13, 14, and 15, creating a candidate sequence consisting of an amino acid sequence in which one, two, or several amino acid residues are substituted, deleted, inserted, and / or added; (b)Selecting a candidate sequence that does not have significant homology (sequence identity) with any known human gene product from the candidate sequences created in (a); (c)Contacting a peptide consisting of the candidate sequence selected in (b) with an APC; (d)Contacting the APC of (c) with CD8-positive T cells; and (e)Selecting a peptide having CTL-inducing ability equal to or higher than that of a peptide consisting of the original amino acid sequence.

[0024] Use of at least one active ingredient selected from the group consisting of the following (a) to (e) in the production of a composition for inducing an immune response against coronavirus infection: (a)One or more peptides according to any one of [1] to [5]; (b)One or more polynucleotides encoding a peptide according to any one of [1] to [5] in an expressible form; (c)An antigen-presenting cell (APC) that presents a complex of a peptide according to any one of [1] to [5] and an HLA antigen on the surface of its own cells; (d)An exosome that presents a complex of a peptide according to any one of [1] to [5] and an HLA antigen on the surface of its own cells; and CTLs targeting the peptide according to any one of [1] to [5].

[0025] Use of at least one active ingredient selected from the group consisting of the following (a) to (e) in the manufacture of a pharmaceutical composition for any one or more purposes selected from the treatment, prevention, and suppression of exacerbation of coronavirus infection: (a) One or more peptides according to any one of [1] to [5]; (b) One or more polynucleotides encoding the peptide according to any one of [1] to [5] in an expressible form; (c) Antigen-presenting cells (APCs) presenting a complex of the peptide according to any one of [1] to [5] and an HLA antigen on their cell surface; (d) Exosomes presenting a complex of the peptide according to any one of [1] to [5] and an HLA antigen on their cell surface; and (e) CTLs targeting the peptide according to any one of [1] to [5].

[0026] Use of at least one active ingredient selected from the group consisting of the following (a) to (e) for inducing an immune response against coronavirus infection: (a) One or more peptides according to any one of [1] to [5]; (b) One or more polynucleotides encoding the peptide according to any one of [1] to [5] in an expressible form; (c) Antigen-presenting cells (APCs) presenting a complex of the peptide according to any one of [1] to [5] and an HLA antigen on their cell surface; (d) Exosomes presenting a complex of the peptide according to any one of [1] to [5] and an HLA antigen on their cell surface; and (e) CTLs targeting the peptide according to any one of [1] to [5].

[0027] Use of at least one active ingredient selected from the group consisting of the following (a) to (e) for any one or more purposes selected from the treatment, prevention, and suppression of exacerbation of coronavirus infection: (a) One or more peptides according to any one of [1] to [5]; (b) One or more polynucleotides encoding a peptide according to any one of [1] to [5] in an expressible form; (c) Antigen-presenting cells (APCs) presenting a complex of a peptide according to any one of [1] to [5] and an HLA antigen on the surface of its own cells; (d) Exosomes presenting a complex of a peptide according to any one of [1] to [5] and an HLA antigen on the surface of its own cells; and (e) CTLs targeting a peptide according to any one of [1] to [5].

[0028] A method for inducing cytotoxic activity against coronavirus-infected cells, comprising the step of administering to a subject at least one active ingredient selected from the group consisting of the following (a) to (e): (a) One or more peptides according to any one of [1] to [5]; (b) One or more polynucleotides encoding a peptide according to any one of [1] to [5] in an expressible form; (c) Antigen-presenting cells (APCs) presenting a complex of a peptide according to any one of [1] to [5] and an HLA antigen on the surface of its own cells; (d) Exosomes presenting a complex of a peptide according to any one of [1] to [5] and an HLA antigen on the surface of its own cells; and (e) CTLs targeting a peptide according to any one of [1] to [5].

[0029] A lyophilized preparation containing one or more peptides according to any one of [1] to [5].

[0030] A pharmaceutical composition prepared by a method comprising dissolving one or more peptides according to any one of [1] to [5] in a water-soluble carrier and filter-sterilizing.

[0031] An aqueous solution containing one or more peptides according to any one of [1] to [5] and a water-soluble carrier, which is filter-sterilized.

[0032] An emulsion comprising one or more peptides according to any one of [1] to [5], a water-soluble carrier, and an oil adjuvant.

[0033] A kit comprising a container containing a pharmaceutical composition according to any one of [9] to

[0013] and a container containing an adjuvant.

[0034] A kit comprising a container containing a lyophilized preparation comprising a peptide according to any one of [1] to [5], a container containing an adjuvant, and a container containing a reconstitution solution for the lyophilized preparation.

[0035] A kit comprising a container containing a composition according to any one of [7] to

[0013] and a container containing an adjuvant.

[0036] A T cell receptor α chain comprising a CDR3 specified by any amino acid sequence selected from the group consisting of SEQ ID NOs: 32, 34, 36 and 38, or a CDR3 functionally equivalent thereto.

[0037] A T cell receptor β chain comprising a CDR3 specified by any amino acid sequence selected from the group consisting of SEQ ID NOs: 33, 35, 37 and 39, or a CDR3 functionally equivalent thereto.

[0038] A T cell receptor comprising a combination of any T cell receptor α chain according to

[0036] and any T cell receptor β chain according to

[0037] .

[0039] The T cell receptor according to

[0038] , wherein the amino acid sequences of the CDR3s of the T cell receptor α chain and the T cell receptor β chain are any of the following combinations: CDR3 of T cell receptor α chain CDR3 of T cell receptor β chain SEQ ID NO: 32 SEQ ID NO: 33, SEQ ID NO: 34 SEQ ID NO: 35, SEQ ID NO: 36 SEQ ID NO: 37, and SEQ ID NO: 38 SEQ ID NO: 39.

[0040] A polynucleotide encoding any one of the T cell receptor α chains described in

[0036] and any one of the T cell receptor β chains described in

[0037] .

[0041] A TCR that recognizes any of the peptides described in [1]-[5] presented on an APC by an HLA antigen.

[0042] A method for determining SARS-CoV-2 infection, comprising the following steps: (a) Extracting gDNA from PBMCs derived from a subject, or extracting cDNA using RNA extracted from PBMCs as a template, or synthesizing cDNA using RNA extracted from PBMCs as a template; (b) Using NGS (next-generation sequencer) to comprehensively decode the TCRα gene sequence and TCRβ gene sequence from gDNA or cDNA and determine the TCR repertoire; (c) Profiling the TCR repertoire using SARS-CoV-2-derived peptide-reactive TCR as an indicator and evaluating the presence of SARS-CoV-2-specific T cells induced by infection.

[0043] The method of

[0042] , wherein the SARS-CoV-2-derived peptide-reactive TCR is the TCR of

[0041] .

[0044] The method of

[0043] , wherein the TCR comprises an amino acid sequence selected from the group consisting of SEQ ID NOs: 32-39. Although the present invention has been described in detail herein with respect to its specific embodiments, it should be understood that the foregoing description is in fact exemplary and explanatory and is intended to illustrate the present invention and its preferred embodiments. Those skilled in the art will readily understand that various changes and modifications can be made therein without departing from the spirit and scope of the present invention through conventional experiments. Therefore, the present invention is not intended to be defined by the above description, but is intended to be defined by the appended claims and their equivalents. Hereinafter, the present invention will be described in more detail with reference to examples. However, the following materials, methods, and examples may be useful for assisting those skilled in the art in the preparation and use of certain forms of the present invention, but are only for the purpose of explaining aspects of the present invention and are therefore not intended to limit the scope of the present invention in any way. Those skilled in the art can use methods and materials similar or equivalent to those described herein in the practice or testing of the present invention. Materials and Methods Cell Lines The T2 cell (HLA-A * 02:01 / −), a human lymphoblastoid cell line, was purchased from ATCC. The TISI cell (HLA-A * 24:02 / −), a human lymphoblastoid-like cell line, was purchased from the International Histocompatibility Working Group. Selection of SARS-CoV-2-derived Peptides 9mer and 10mer peptides derived from SARS-CoV-2 proteins expected to bind to HLA-A * 02:01 were determined using the binding prediction server "NetMHC 4.0" (http: / / www.cbs.dtu.dk / services / NetMHC / ) (Nielsen M et al., Protein Sci 2003, 12(5):1007-1017; Andreatta M et al., Bioinformatics 2016, 32(4):511-517). Among them, peptides commonly found in SARS-CoV Tor2 (GenBank accession number AY274119), SARS-CoV BJ01 (GenBank accession number AY278488), SARS-CoV GZ02 (GenBank accession number AY390556), and MERS-CoV (GenBank accession number JX869059) were selected as epitope candidates (Kiyotani K et al., J Hum Genet 2020, 65(7):569-575). Peptide Synthesis The peptide was synthesized by Cosmo Bio Co., Ltd. (Tokyo, Japan) according to the solid-phase synthesis method and purified by reverse-phase high-performance liquid chromatography (HPLC). The quality of the peptide (purity of 90% or higher) was guaranteed by HPLC and mass spectrometry. The peptide was dissolved in dimethyl sulfoxide (final concentration: 20 mg / ml) and stored at -80°C. CTL induction in vitro Monocyte-derived dendritic cells (DCs) were used as antigen-presenting cells to induce specific cytotoxic T lymphocytes (CTLs) against peptides presented on human leukocyte antigen (HLA). As previously reported in the literature, DCs were generated in vitro (Nakahara S et al., Cancer Res 2003, 63(14):4112-4118). Specifically, peripheral blood mononuclear cells (PBMCs) collected from healthy human volunteers (HLA-A * 02:01 positive or HLA-A * 24:02 positive) were seeded into tissue culture dishes (Corning), and monocytes in the PBMCs were allowed to adhere to the dishes. The cells were cultured for 7 days in the presence of 1000 IU / ml granulocyte-macrophage colony-stimulating factor (R&D System) and 1000 IU / ml interleukin (IL)-4 (R&D System). AIM-V medium (Invitrogen) containing heat-inactivated AB-type serum (MP Biomedicals) was used as the culture medium (2% ABS / AIM-V medium). In 48-well plates (Corning), DCs differentiated from monocytes by cytokines and autologous CD8-positive T cells obtained using a CD8 Positive Isolation Kit (Invitrogen) were mixed at a ratio of 1:20 (1.5 x 10 4 cells of DCs and 3 x 10 5Individual CD8-positive T cells) were mixed. Furthermore, a peptide was added (final peptide concentration: 20 μg / ml). The amount of 2% ABS / AIM-V medium per well was 0.5 ml, and IL-7 (R&D System) and IL-21 (Cell Genix) were added (final concentration: IL-7 10 ng / ml, IL-21 30 ng / ml). Three days after the start of culture, DC and peptide were added again (final peptide concentration: 20 μg / ml). DC was freshly prepared by the same method as above. Seven days after the start of culture, IL-2 (Novartis), IL-7, and IL-15 (Novoprotein) were added (final concentration: IL-2 48 IU / ml, IL-7 5 ng / ml, and IL-15 5 ng / ml) (Wolfl M et al., Nat Protoc 2014, 9(4):950-966). CTL proliferation procedure CTLs were expanded using a method similar to that reported by Riddell et al. (Walter EA et al., N Engl J Med 1995, 333(16): 1038-1044; Riddell SR et al., Nat Med 1996, 2(2): 216-223). In tissue culture flasks (FALCON), CTLs were cultured in 5% ABS / AIM-V medium together with two types of human B lymphoblastoid cell lines treated with mitomycin C (each 5 x 10 6 cells) and anti-CD3 antibody (BD biosciences, final concentration: 40 ng / ml) (culture volume: 25 ml / flask). On the day after the start of culture, IL-2 was added to the culture (final IL-2 concentration: 120 IU / ml). On days 5, 8, and 11, medium replacement was performed with 5% ABS / AIM-V medium containing 60 IU / ml of IL-2 (final IL-2 concentration: 30 IU / ml) (Yoshimura S et al., PLoS One 2014, 9(1):e85267). Confirmation of IFN-γ production To confirm the peptide-specific IFN-γ production of CTL induced using peptides, IFN-γ ELISPOT assay and IFN-γ ELISA were performed. T2 cells or TISI cells pulsed with peptides were prepared as target cells. IFN-γ ELISPOT assay and IFN-γ ELISA were performed according to the procedures recommended by the assay kit manufacturer. Results Selection of HLA-A * 02:01-binding peptides Table 2 shows 9mer and 10mer peptides derived from SARS-CoV-2 proteins predicted to bind to HLA-A * 02:01 in descending order of binding affinity. A total of 15 peptides were selected as candidate epitope peptides that may have the ability to bind to HLA-A * 02:01. The numbers at the positions indicate the position of the first amino acid of the peptide counted from the N-terminus of the protein. The binding affinity (nM) was calculated using "NetMHC4.0". Induction of HLA-A * 02:01-restricted CTL HLA-A *02:01 Using positive PBMCs, SARS-CoV-2 protein-derived peptide-specific CTLs were induced according to the protocol described in "Materials and Methods". Peptide-specific IFN-γ production of the cells was confirmed by ELISPOT assay (Figure 1). Peptide-specific IFN-γ production was observed for Peptide 1 (SEQ ID NO: 1), Peptide 2 (SEQ ID NO: 2), Peptide 3 (SEQ ID NO: 3), Peptide 4 (SEQ ID NO: 4), Peptide 5 (SEQ ID NO: 5), Peptide 7 (SEQ ID NO: 7), Peptide 9 (SEQ ID NO: 9), Peptide 10 (SEQ ID NO: 10), Peptide 11 (SEQ ID NO: 11), Peptide 12 (SEQ ID NO: 12), Peptide 13 (SEQ ID NO: 13), Peptide 14 (SEQ ID NO: 14), and Peptide 15 (SEQ ID NO: 15) (Figure 1a). On the other hand, specific IFN-γ production against the other peptides shown in Table 2 was not observed. For example, specific IFN-γ production against Peptide 8 (SEQ ID NO: 8) was not observed (Figure 1b). Any of the peptides might bind to HLA-A ＊ 02:01, but as a result, 13 peptides that bound to HLA-A * 02:01 and had CTL-inducing ability were identified. Establishment of HLA-A ＊ 02:01-restricted CTL lines In the HLA-A ＊ 02:01-restricted IFN-γ ELISPOT assay, cells showing specific IFN-γ production against Peptide 2 (SEQ ID NO: 2), Peptide 3 (SEQ ID NO: 3), Peptide 4 (SEQ ID NO: 4), Peptide 7 (SEQ ID NO: 7), Peptide 10 (SEQ ID NO: 10), Peptide 11 (SEQ ID NO: 11), Peptide 12 (SEQ ID NO: 12), or Peptide 15 (SEQ ID NO: 15) were grown to obtain HLA-A ＊02:01 An HLA-A-restricted CTL line was established. As a result of IFN-γ measurement by ELISA, HLA-A pulsed with peptide 2 (SEQ ID NO: 2), peptide 3 (SEQ ID NO: 3), peptide 4 (SEQ ID NO: 4), peptide 7 (SEQ ID NO: 7), peptide 10 (SEQ ID NO: 10), peptide 11 (SEQ ID NO: 11), peptide 12 (SEQ ID NO: 12) or peptide 15 (SEQ ID NO: 15) * 02:01 IFN-γ production of the CTL line against HLA-A-expressing target cells (T2 cells) was observed (Figure 2). From this, it was clearly demonstrated that peptide 2 (SEQ ID NO: 2), peptide 3 (SEQ ID NO: 3), peptide 4 (SEQ ID NO: 4), peptide 7 (SEQ ID NO: 7), peptide 10 (SEQ ID NO: 10), peptide 11 (SEQ ID NO: 11), peptide 12 (SEQ ID NO: 12) and peptide 15 (SEQ ID NO: 15) bind to HLA-A * 02:01 and have CTL-inducing ability. Induction of HLA-A-restricted CTLs by SARS-CoV-2 protein-derived peptides * 24:02 Induction of restricted CTLs HLA-A * Peptide 1 (SEQ ID NO: 1), peptide 2 (SEQ ID NO: 2), peptide 3 (SEQ ID NO: 3), peptide 4 (SEQ ID NO: 4), peptide 5 (SEQ ID NO: 5), peptide 7 (SEQ ID NO: 7), peptide 9 (SEQ ID NO: 9), peptide 10 (SEQ ID NO: 10), peptide 11 (SEQ ID NO: 11), peptide 12 (SEQ ID NO: 12), peptide 13 (SEQ ID NO: 13), peptide 14 (SEQ ID NO: 14) and peptide 15 (SEQ ID NO: 15), which were confirmed to have HLA-A-restricted CTL-inducing ability, were used to verify whether they have HLA-A * 24:02 restricted CTL-inducing ability. HLA-A * 24:02 Using HLA-A-positive PBMCs *24:02 Restricted CTLs were induced according to the protocol described in "Materials and Methods". Peptide-specific IFN-γ production of the cells was confirmed by ELISPOT assay (Figure 3). Peptide-specific IFN-γ production was observed for Peptide 3 (SEQ ID NO: 3) and Peptide 11 (SEQ ID NO: 11) (Figure 3a). On the other hand, specific IFN-γ production against Peptide 1 (SEQ ID NO: 1), Peptide 2 (SEQ ID NO: 2), Peptide 4 (SEQ ID NO: 4), Peptide 5 (SEQ ID NO: 5), Peptide 7 (SEQ ID NO: 7), Peptide 9 (SEQ ID NO: 9), Peptide 10 (SEQ ID NO: 10), Peptide 12 (SEQ ID NO: 12), Peptide 13 (SEQ ID NO: 13), Peptide 14 (SEQ ID NO: 14) and Peptide 15 (SEQ ID NO: 15) was not observed. The result of Peptide 4 (SEQ ID NO: 4) is shown as an example (Figure 3b). From the above, HLA-A ＊ 02:01 Peptides 3 (SEQ ID NO: 3) and 11 (SEQ ID NO: 11) having the ability to induce restricted CTLs also bind to HLA-A * 24:02 and were shown to have the ability to induce HLA-A * 24:02 restricted CTLs. Establishment of HLA-A ＊ 24:02 restricted CTL lines specific for SARS-CoV-2 protein-derived peptides HLA-A ＊ Cells showing specific IFN-γ production against Peptide 3 (SEQ ID NO: 3) or Peptide 11 (SEQ ID NO: 11) in the HLA-A ＊ 24:02 restricted IFN-γ ELISPOT assay were expanded to establish HLA-A * 24:02 restricted CTL lines. As a result of IFN-γ measurement by ELISA, IFN-γ production of the CTL lines against HLA-A ＊ 02:01 target cells (TISI cells) pulsed with Peptide 3 (SEQ ID NO: 3) or Peptide 11 (SEQ ID NO: 11) was observed (Figure 4). From this, HLA-A * 02:01 Peptides 3 (SEQ ID NO: 3) and 11 (SEQ ID NO: 11) having the ability to induce restricted CTLs also bind to HLA-A *It was clearly demonstrated that it has the ability to induce restrictive CTL. Peptide homology analysis Peptides 1 (SEQ ID NO: 1), 2 (SEQ ID NO: 2), 3 (SEQ ID NO: 3), 4 (SEQ ID NO: 4), 5 (SEQ ID NO: 5), 7 (SEQ ID NO: 7), 9 (SEQ ID NO: 9), 10 (SEQ ID NO: 10), 11 (SEQ ID NO: 11), 12 (SEQ ID NO: 12), 13 (SEQ ID NO: 13), 14 (SEQ ID NO: 14) and 15 (SEQ ID NO: 15) were confirmed to be able to induce CTLs that show peptide-specific IFN-γ production. Therefore, to confirm the homology between the amino acid sequences of peptides 1 (SEQ ID NO: 1), 2 (SEQ ID NO: 2), 3 (SEQ ID NO: 3), 4 (SEQ ID NO: 4), 5 (SEQ ID NO: 5), 7 (SEQ ID NO: 7), 9 (SEQ ID NO: 9), 10 (SEQ ID NO: 10), 11 (SEQ ID NO: 11), 12 (SEQ ID NO: 12), 13 (SEQ ID NO: 13), 14 (SEQ ID NO: 14) and 15 (SEQ ID NO: 15) and the amino acid sequences derived from human proteins, homology analysis was performed using the BLAST algorithm (http: / / blast.ncbi.nlm.nih.gov / Blast.cgi). As a result, the amino acid sequences of peptides 1 (SEQ ID NO: 1), 2 (SEQ ID NO: 2), 3 (SEQ ID NO: 3), 4 (SEQ ID NO: 4), 5 (SEQ ID NO: 5), 7 (SEQ ID NO: 7), 9 (SEQ ID NO: 9), 10 (SEQ ID NO: 10), 11 (SEQ ID NO: 11), 12 (SEQ ID NO: 12), 13 (SEQ ID NO: 13), 14 (SEQ ID NO: 14) and 15 (SEQ ID NO: 15) were not found in human proteins. Therefore, as far as the inventors know, these peptides are derived from SARS-CoV-2 or SARS-CoV and are considered to have little potential to cause unintended immune responses against normal human tissues. In conclusion, novel HLA-A derived from SARS-CoV-2 protein *02:01 Restrictive epitope peptides were identified. Some of them were also HLA-A * 24:02 Identified as restrictive epitope peptides. It was shown that these peptides can be applied to peptide vaccines against COVID-19. Materials and Methods Cell Lines HEV0011 cells (HLA-A * 02:06 / −), an Epstein-Barr virus-transformed B cell line, was purchased from the RIKEN BioResource Research Center. Selection of SARS-CoV-2-Derived Peptides Peptides derived from SARS-CoV-2 proteins that are expected to bind to HLA-A * 02:06 were determined using the binding prediction server "NetMHC 4.0" (http: / / www.cbs.dtu.dk / services / NetMHC / ) (Nielsen M et al., Protein Sci 2003, 12(5):1007-1017; Andreatta M et al., Bioinformatics 2016, 32(4):511-517). Among them, peptides commonly observed in SARS-CoV Tor2 (GenBank accession number AY274119), SARS-CoV BJ01 (GenBank accession number AY278488), and SARS-CoV GZ02 (GenBank accession number AY390556) were selected as epitope candidates (Kiyotani K et al., J Hum Genet 2020, 65(7):569-575). Peptide Synthesis Peptides were synthesized by Cosmo Bio Co., Ltd. (Tokyo, Japan) according to the solid-phase synthesis method and purified by reverse-phase high-performance liquid chromatography (HPLC). The quality (purity of 90% or more) of the peptides was guaranteed by HPLC and mass spectrometry. The peptides were dissolved in dimethyl sulfoxide (final concentration: 20 mg / ml) and stored at -80°C. CTL Induction In Vitro Monocyte-derived dendritic cells (DCs) were used as antigen-presenting cells to induce specific cytotoxic T lymphocytes (CTLs) against peptides presented on human leukocyte antigen (HLA). As already reported in the literature, DCs were generated in vitro (Nakahara S et al., Cancer Res 2003, 63(14):4112-4118). Specifically, peripheral blood mononuclear cells (PBMCs) collected from healthy human volunteers (HLA-A * 02:06 positive) were seeded into tissue culture dishes (Corning), and monocytes in the PBMCs were allowed to adhere to the dishes. Monocytes were cultured for 7 days in the presence of 1000 IU / ml granulocyte-macrophage colony-stimulating factor (R&D System) and 1000 IU / ml interleukin (IL)-4 (R&D System). As the culture medium, AIM-V medium (Invitrogen) containing heat-inactivated AB-type serum (MP Biomedicals) was used (2% ABS / AIM-V medium). In 48-well plates (Corning), DCs differentiated from monocytes by cytokines and autologous CD8-positive T cells obtained using a CD8 Positive Isolation Kit (Invitrogen) were mixed at a ratio of 1:20 (1.5 x 10 4 cells of DCs and 3 x 10 5 cells of CD8-positive T cells). Furthermore, peptides were added (final peptide concentration: 20 μg / ml). The amount of 2% ABS / AIM-V medium per well was 0.5 ml, and IL-7 (R&D System) and IL-21 (Cell Genix) were added (final concentrations: IL-7 10 ng / ml, IL-21 30 ng / ml). Three days after the start of culture, DCs and peptides were added again (final peptide concentration: 20 μg / ml). DCs were freshly prepared by the same method as above. Seven days after the start of culture, IL-2 (Novartis), IL-7, and IL-15 (Novoprotein) were added (final concentrations: IL-2 48 IU / ml, IL-7 5 ng / ml, and IL-15 5 ng / ml) (Wolfl M et al., Nat Protoc 2014, 9(4):950-966). CTL Expansion Procedure CTLs were expanded using a method similar to that reported by Riddell et al. (Walter EA et al., N Engl J Med 1995, 333(16): 1038-1044; Riddell SR et al., Nat Med 1996, 2(2): 216-223). In a tissue culture flask (FALCON), CTLs were cultured in 5% ABS / AIM-V medium (culture volume: 25 ml / flask) with two types of human B lymphoblastoid cell lines treated with mitomycin C (5 x 10 6 each) and anti-CD3 antibody (BD biosciences, final concentration: 40 ng / ml). On the day after starting the culture, IL-2 was added to the culture (IL-2 final concentration: 120 IU / ml). On days 5, 8, and 11, medium replacement was performed with 5% ABS / AIM-V medium containing 60 IU / ml of IL-2 (IL-2 final concentration: 30 IU / ml) (Yoshimura S et al., PLoS One 2014, 9(1):e85267). Confirmation of IFN-γ production To confirm the peptide-specific IFN-γ production of CTLs induced with peptides, IFN-γ ELISPOT assay and IFN-γ ELISA were performed. HEV0011 cells pulsed with peptides were prepared as target cells. IFN-γ ELISPOT assay and IFN-γ ELISA were performed according to the procedures recommended by the assay kit manufacturer. Results Selection of HLA-A * 02:06-binding peptides derived from SARS-CoV-2 proteins Table 3 shows 10-mer peptides derived from SARS-CoV-2 proteins predicted to bind to HLA-A * 02:06 by "NetMHC 4.0". A total of eight peptides were selected as candidate epitope peptides that may have the ability to bind to HLA-A * 02:06. The numbers in the position indicate the position of the first amino acid of the peptide counted from the N-terminus of the protein. The binding affinity (nM) was calculated using "NetMHC4.0". Induction of HLA-A * 02:06-restricted CTLs by SARS-CoV-2 protein-derived peptides HLA-A * Using HLA-A 02:06-positive PBMCs, SARS-CoV-2 protein-derived peptide-specific CTLs were induced according to the protocol described in "Materials and Methods". Peptide-specific IFN-γ production of the cells was confirmed by ELISPOT assay (Figure 5). Peptide-specific IFN-γ production was observed for Peptide 3 (SEQ ID NO: 3), Peptide 4 (SEQ ID NO: 4), Peptide 7 (SEQ ID NO: 7), Peptide 10 (SEQ ID NO: 10), Peptide 11 (SEQ ID NO: 11), Peptide 12 (SEQ ID NO: 12), and Peptide 15 (SEQ ID NO: 15) (Figure 5a). On the other hand, specific IFN-γ production against other peptides shown in Table 3 was not observed. For example, specific IFN-γ production against Peptide 2 (SEQ ID NO: 2) was not observed (Figure 5b). Although any of the peptides might have the possibility of binding to HLA-A * 02:06, seven peptides that bound to HLA-A * 02:06 and had CTL-inducing ability were identified. Establishment of HLA-A * 02:06-restricted CTL lines by SARS-CoV-2 protein-derived peptides HLA-A * 02:06-restricted IFN-γ ELISPOT assay, cells showing specific IFN-γ production against Peptide 3 (SEQ ID NO: 3), Peptide 4 (SEQ ID NO: 4), Peptide 7 (SEQ ID NO: 7), Peptide 10 (SEQ ID NO: 10), Peptide 11 (SEQ ID NO: 11), Peptide 12 (SEQ ID NO: 12), or Peptide 15 (SEQ ID NO: 15) were expanded to obtain HLA-A *02:06 Established a restricted CTL line. As a result of IFN-γ measurement by ELISA, HLA-A pulsed with peptide 3 (SEQ ID NO: 3), peptide 4 (SEQ ID NO: 4), peptide 7 (SEQ ID NO: 7), peptide 10 (SEQ ID NO: 10), peptide 11 (SEQ ID NO: 11), peptide 12 (SEQ ID NO: 12) or peptide 15 (SEQ ID NO: 15) * 02:06 IFN-γ production of the CTL line against the expression target cells (HEV0011 cells) was observed (Figure 6). From this, peptide 3 (SEQ ID NO: 3), peptide 4 (SEQ ID NO: 4), peptide 7 (SEQ ID NO: 7), peptide 10 (SEQ ID NO: 10), peptide 11 (SEQ ID NO: 11), peptide 12 (SEQ ID NO: 12) and peptide 15 (SEQ ID NO: 15) are HLA-A * 02:06 was clearly demonstrated to bind and have CTL-inducing ability. Homology analysis of peptides Peptide 3 (SEQ ID NO: 3), Peptide 4 (SEQ ID NO: 4), Peptide 7 (SEQ ID NO: 7), Peptide 10 (SEQ ID NO: 10), Peptide 11 (SEQ ID NO: 11), Peptide 12 (SEQ ID NO: 12), and Peptide 15 (SEQ ID NO: 15) were confirmed to be able to induce CTLs that show peptide-specific IFN-γ production. Therefore, in order to confirm the homology between the amino acid sequences of Peptide 3 (SEQ ID NO: 3), Peptide 4 (SEQ ID NO: 4), Peptide 7 (SEQ ID NO: 7), Peptide 10 (SEQ ID NO: 10), Peptide 11 (SEQ ID NO: 11), Peptide 12 (SEQ ID NO: 12), and Peptide 15 (SEQ ID NO: 15) and the amino acid sequences derived from human proteins, homology analysis was performed using the BLAST algorithm (http: / / blast.ncbi.nlm.nih.gov / Blast.cgi). As a result, the amino acid sequences of Peptide 3 (SEQ ID NO: 3), Peptide 4 (SEQ ID NO: 4), Peptide 7 (SEQ ID NO: 7), Peptide 10 (SEQ ID NO: 10), Peptide 11 (SEQ ID NO: 11), Peptide 12 (SEQ ID NO: 12), and Peptide 15 (SEQ ID NO: 15) were not found in human proteins. Therefore, as far as the inventors know, these peptides are derived from SARS-CoV-2 or SARS-CoV and are considered to have little possibility of causing unintended immune responses against normal human tissues. In conclusion, a novel HLA-A * 02:06-restricted epitope peptide derived from SARS-CoV-2 protein was identified. Materials and Methods CTL Induction In Vitro Monocyte-derived dendritic cells (DCs) were used as antigen-presenting cells to induce specific cytotoxic T lymphocytes (CTLs) against peptides presented on human leukocyte antigen (HLA). As previously reported in the literature, DCs were prepared in vitro (Nakahara S et al., Cancer Res 2003, 63(14):4112-4118). Specifically, healthy human volunteers (HLA-A *Peripheral blood mononuclear cells (PBMCs) collected from 4 (positive) were seeded into a tissue culture dish (Corning), and monocytes in the PBMCs were allowed to adhere to the dish. They were cultured for 7 days in the presence of 1000 IU / ml granulocyte macrophage colony-stimulating factor (R&D System) and 1000 IU / ml interleukin (IL)-4 (R&D System). AIM-V medium (Invitrogen) containing heat-inactivated AB type serum (MP Biomedicals) was used as the medium (2% ABS / AIM-V medium). In a 48-well plate (Corning), dendritic cells (DCs) induced to differentiate from monocytes by cytokines and autologous CD8-positive T cells obtained using a CD8 Positive Isolation Kit (Invitrogen) were mixed at a ratio of 1:20 (1.5 x 10 5 DCs and 3 x 10 Establishment of CTL clones (limiting dilution method) After CTL induction in vitro, the cells were seeded into a 96-well round-bottom microplate (Corning) at a density of 1 cell / well. Two types of human B lymphoblastoid cell lines treated with mitomycin C (each 1 x 10 4Cells were cultured (150 μl / well of culture medium volume) together with anti-CD3 antibody (final concentration: 30 ng / ml) and IL-2 (final concentration: 150 IU / ml). AIM-V medium containing heat-inactivated AB type serum (SIGMA) was used as the medium (5% ABS / AIM-V medium). After 10 days, 50 μl of 5% ABS / AIM-V medium containing 600 IU / ml of IL-2 was added to the culture (Uchida N et al., Clin Cancer Res 2004, 10(24):8577-8586; Suda T et al., Cancer Sci 2006, 97(5):411-419; Watanabe T et al., Cancer Sci 2005, 96(8):498-506). After day 14, CTLs showing peptide-specific IFN-γ production in the ELISPOT assay were expanded using the method described above (the CTL expansion procedure described in Example 1). ELISA was performed to re-verify peptide-specific IFN-γ production. The IFN-γ ELISPOT assay and IFN-γ ELISA were performed according to the procedures recommended by the assay kit manufacturer. T2 cells (HLA-A * 02:01 / −) (ATCC) were used as target cells. TCR analysis RNA was extracted from SARS-CoV-2 protein-derived peptide-specific CTL clones using the RNeasy mini kit, and then cDNA was synthesized. The nucleotide sequences of the TCRα chain and TCRβ chain were decoded by Sanger sequence analysis. After TA cloning, the nucleotide sequence of the TCRα chain was determined using the M13 forward primer (5’-TGTAAAACGACGGCCAGTG-3’, SEQ ID NO: 40) or 5’-CTGGCCGTCGTTTTAC-3’ (SEQ ID NO: 41) and the M13 reverse primer (5’-CAGGAAACAGCTATGACCAT-3’, SEQ ID NO: 42) or 5’-CAGGAAACAGCTATGAC-5’ (SEQ ID NO: 43). For the determination of the nucleotide sequence of the TCRβ chain, the forward primer (5’-GTCTCGTGGGCTCGGAGATGTGTATAAGAGACAGTATCAACGCAGAGTGGCCAT-3’, SEQ ID NO: 44) and the reverse primer (5’-TCGTCGGCAGCGTCAGATGTGTATAAGAGACAGDVHDVTCTGATGGCTCAAACACAGC-3’, SEQ ID NO: 45) were used. The nucleotide sequences of the TCRα gene and TCRβ gene registered in the IMGT / GENE-DB, a database of TCR (Giudicelli V et al., Nucleic Acids Res 2005, 33(Database issue):D256-261), were referred to. Establishment of peptide-specific CTL clones CTL clones recognizing SARS-CoV-2 protein-derived peptides were established by the limiting dilution method. As a result of IFN-γ measurement by ELISA, the CTL clones showed specific IFN-γ production against peptide 7 (SEQ ID NO: 7), peptide 10 (SEQ ID NO: 10), and peptide 12 (SEQ ID NO: 12) (Figure 7). From this, it was confirmed that the CTL clones recognized SARS-CoV-2 protein-derived peptides presented by HLA. Two clones were established as CTLs recognizing peptide 12 (SEQ ID NO: 12). Identification of TCRs expressed by peptide-specific CTL clones By Sanger sequencing analysis, the CDR3 amino acid sequences of TCRs expressed by SARS-CoV-2 protein-derived peptide-specific CTL clones were identified (Table 4). Materials and Methods PBMC PBMC from SARS-CoV-2 non-infected individuals (HLA-A * 02:01 positive) collected before December 2019 were purchased from Cellular Technology Limited. Culture of PBMC PBMC collected from SARS-CoV-2 non-infected individuals were seeded into 48-well multi-well plates (Corning) at a density of 5x10 5 cells / well and cultured for 12 days. Complete medium containing inactivated fetal bovine serum (GIBCO) (a medium prepared by mixing equal volumes of RPMI1640 medium and AIM-V medium) was used. Peptides were added on the starting day of culture and 4 days later (final concentration: 10 μg / ml). IL-2 was added 5, 7, and 10 days after the start of culture (final concentration: 120 IU / ml). The cultured PBMC were used for the tetramer assay. Preparation of Tetramer QuickSwitch TM Quant HLA-A * Using the QuickSwitch Quant HLA-A 02:01 Tetramer Kit-PE (MBL International Corporation), tetramers were prepared according to the manufacturer's recommended procedure. 50 μl of the Exiting peptide-bound QuickSwitch TM Tetramer was mixed with 1 μl of a 1 mg / ml peptide solution. Additionally, 1 μl of Peptide Exchange Factor was added and the mixture was left standing at room temperature for 4 hours or more, resulting in the replacement of the Exiting peptide with Peptide 3 (SEQ ID NO: 3) to obtain the tetramer. Tetramer Assay For PBMCs derived from SARS-CoV-2 non-infected individuals, a tetramer assay was performed. Since T cells that recognize peptides bind to tetramers via TCR, PBMCs were treated with 450 nM Dasatinib (Cayman Chemical) (37 °C, 30 minutes) to maintain the expression of TCR on the T cell surface (Lissina A et al., J Immunol Methods 2009, 340(1):11-24). After staining PBMCs with tetramers, they were further stained with FITC-labeled anti-CD8 antibody, APC-labeled anti-CD3 antibody, and PE-Cy7-labeled anti-CD4 antibody (all from BD Biosciences). Finally, they were stained with a 0.1 μg / ml DAPI solution (BD Biosciences), and analysis was performed using a flow cytometer (SH800 cell sorter, Sony). Tetramer-positive CD8-positive T cells in the DAPI-negative CD3-positive CD4-negative cell population were confirmed. A PE-labeled HIV tetramer (Medical & Biological Laboratories Co., Ltd.) was used as a negative control. Results Detection of tetramer-positive CD8-positive T cells CD8-positive T cells that recognize peptide 3 (SEQ ID NO: 3) were detected from PBMCs of SARS-CoV-2 non-infected individuals (Figure 8). It was confirmed that peptide 3 (SEQ ID NO: 3) could be recognized by some (cross-reactive T cells) of the CTLs induced by foreign antigens in the past. From this result, it was shown that peptide 3 (SEQ ID NO: 3) could be applied to a peptide vaccine against COVID-19 as an antigen that stimulates T cells and induces cellular immunity. Materials and methods PBMC PBMCs are collected from subjects (HLA-A * 02:01 or HLA-A * 02:06 positive) whose past SARS-CoV-2 infection history is to be investigated. In addition, PBMCs derived from SARS-CoV-2 non-infected individuals (HLA-A * 02:01 or HLA-A * 02:06 positive) collected before December 2019 are purchased from Cellular Technology Limited. TCR analysis After extracting RNA from PBMC using the RNeasy mini kit, cDNA is synthesized. Alternatively, gDNA (Genomic DNA) is extracted from PBMC. Using a next-generation sequencer, sequence analysis of TCR-α and TCR-β is performed to conduct TCR repertoire analysis. To determine the nucleotide sequence of CDR3, the following primers are used. Forward primer (adapter sequence common to TCR-α and TCR-β, SEQ ID NO: 44): 5'-GTCTCGTGGGCTCGGAGATGTGTATAAGAGACAGTATCAACGCAGAGTGGCCAT-3' Reverse primer for TCR-α (SEQ ID NO: 46): 5'-TCGTCGGCAGCGTCAGATGTGTATAAGAGACAGDBDHHCAGGGTCAGGGTTCTGGATA-3' Reverse primer for TCR-β (SEQ ID NO: 45): 5'-TCGTCGGCAGCGTCAGATGTGTATAAGAGACAGDVHDVTCTGATGGCTCAAACACAGC-3' Results TCR repertoire analysis of subject PBMC Analyze the detection frequency of TCR sequences. If TCRs containing CDR3 of TCRα or TCRβ shown in Table 4 are detected more frequently than in the comparative control (PBMC from SARS-CoV-2 non-infected individuals), it indicates that the subject has been infected with SARS-CoV-2 in the past. The present invention provides novel HLA-A24 or HLA-A02 restricted epitope peptides derived from SARS-CoV-2 proteins that can induce a strong and specific immune response against coronavirus infection and thus have applicability to a wide variety of coronavirus infections. The peptides, compositions, APCs, and CTLs of the present invention can be used as peptide vaccines against coronavirus infections, such as SARS-CoV-2, MERS-CoV, or SARS-CoV infections. Also, the TCR sequences induced by the peptides of the present invention can be used in a method for detecting the infection history of SARS-CoV-2 infection. In this specification, the present invention has been described in detail with respect to its specific embodiments. However, it should be understood that the foregoing description is essentially illustrative and explanatory, and is intended to describe the present invention and its preferred embodiments. Through conventional experimentation, those skilled in the art will readily recognize that various changes and modifications can be made therein without departing from the spirit and scope of the present invention, the boundaries and limits of which are defined by the appended claims.

Claims

1. A peptide of less than 15 amino acids having cytotoxic T lymphocyte (CTL) inducibility, comprising an amino acid sequence selected from the group consisting of: (a) an amino acid sequence selected from the group consisting of SEQ ID NOs: 3, 12, 1, 2, 4, 5, 7, 9, 10, 11, 13, 14, and 15; and (b) An amino acid sequence in which one, two or several amino acids have been substituted, deleted, inserted and / or added to the amino acid sequence selected from the group consisting of SEQ ID NOs: 3, 12, 1, 2, 4, 5, 7, 9, 10, 11, 13, 14 and 15.

2. 2. The peptide of claim 1, having one or both of the following characteristics with respect to an amino acid sequence selected from the group consisting of SEQ ID NOs: 3, 12, 1, 2, 4, 5, 7, 9, 10, 11, 13, 14 and 15: (a) the second amino acid from the N-terminus is replaced with an amino acid selected from the group consisting of leucine and methionine; and (b) the C-terminal amino acid is replaced with an amino acid selected from the group consisting of valine and leucine.

3. 2. The peptide of claim 1, having one or both of the following characteristics with respect to an amino acid sequence selected from the group consisting of SEQ ID NOs: 3, 12, 4, 7, 10, 11 and 15: (a) the second amino acid from the N-terminus is replaced with an amino acid selected from the group consisting of valine and glutamine; and (b) the C-terminal amino acid is replaced with an amino acid selected from the group consisting of valine and leucine.

4. 2. The peptide of claim 1, having one or both of the following characteristics with respect to an amino acid sequence selected from the group consisting of SEQ ID NOs: 3 and 11: (a) the second amino acid from the N-terminus is replaced with an amino acid selected from the group consisting of phenylalanine, tyrosine, methionine and tryptophan; and (b) the C-terminal amino acid is substituted with an amino acid selected from the group consisting of phenylalanine, leucine, isoleucine, tryptophan, or methionine.

5. The peptide of claim 1, comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 3, 12, 1, 2, 4, 5, 7, 9, 10, 11, 13, 14 and 15.

6. A polynucleotide encoding the peptide according to any one of claims 1 to 5.

7. A composition comprising a pharma- ceutically acceptable carrier and at least one active ingredient selected from the group consisting of (a) to (e) below: (a) one or more peptides according to any one of claims 1 to 5; (b) one or more polynucleotides encoding the peptide of any one of claims 1 to 5 in an expressible form; (c) an antigen-presenting cell (APC) that presents a complex of a peptide according to any one of claims 1 to 5 and an HLA antigen on its cell surface; (d) an exosome that presents a complex of the peptide according to any one of claims 1 to 5 and an HLA antigen on its cell surface; and (e) A CTL that targets the peptide according to any one of claims 1 to 5.

8. The composition according to claim 7, wherein the active ingredient is at least one active ingredient selected from the group consisting of the following (a) to (d), and the composition is for inducing CTLs: (a) one or more peptides according to any one of claims 1 to 5; (b) one or more polynucleotides encoding the peptide of any one of claims 1 to 5 in an expressible form; (c) an antigen-presenting cell (APC) that presents a complex of a peptide according to any one of claims 1 to 5 and an HLA antigen on its cell surface; and (d) An exosome that presents a complex of the peptide according to any one of claims 1 to 5 and an HLA antigen on its cell surface.

9. 8. The composition of claim 7, which is a pharmaceutical composition.

10. The composition of claim 9, which is a pharmaceutical composition for one or more uses selected from the group consisting of (i) treatment of coronavirus infection, (ii) prevention of coronavirus infection, and (iii) suppression of severity of coronavirus infection.

11. The composition of claim 9, for inducing an immune response against coronavirus infection.

12. The composition of claim 10 or 11, wherein the coronavirus of the coronavirus infection is selected from the group consisting of SARS-CoV-2, MERS-CoV and SARS-CoV.

13. The composition of any one of claims 7 to 12, formulated for administration to a subject who is HLA-A24 or HLA-A02 positive.

14. A method for inducing APCs having CTL inducibility in vitro or ex vivo, comprising the steps selected from the group consisting of: (a) contacting APCs with a peptide according to any one of claims 1 to 5 in vitro, ex vivo or in vivo; and (b) introducing a polynucleotide encoding the peptide according to any one of claims 1 to 5 into an APC.

15. A method for inducing CTLs in vitro or ex vivo, comprising the steps selected from the group consisting of: (a) co-culturing CD8 positive T cells with APCs presenting a complex of an HLA antigen and a peptide according to any one of claims 1 to 5 on their surface; (b) co-culturing CD8 positive T cells with exosomes presenting a complex of an HLA antigen and a peptide according to any one of claims 1 to 5 on their surface; and (c) introducing polynucleotides encoding each subunit of a T cell receptor (TCR) capable of binding to a peptide according to any one of claims 1 to 5 presented by an HLA antigen on the cell surface into a CD8-positive T cell.

16. An APC that presents a complex of an HLA antigen and a peptide described in any one of claims 1 to 5 on its surface.

17. The APC of claim 16, induced by the method of claim 14.

18. A CTL that targets the peptide according to any one of claims 1 to 5.

19. The CTL of claim 18, which is induced by the method of claim 15.

20. A method for inducing an immune response against a coronavirus infection, comprising administering to a subject at least one active ingredient selected from the group consisting of (a) to (e) below: (a) one or more peptides according to any one of claims 1 to 5; (b) one or more polynucleotides encoding the peptide of any one of claims 1 to 5 in an expressible form; (c) an antigen-presenting cell (APC) that presents a complex of a peptide according to any one of claims 1 to 5 and an HLA antigen on its cell surface; (d) an exosome that presents a complex of the peptide according to any one of claims 1 to 5 and an HLA antigen on its cell surface; and (e) A CTL that targets the peptide according to any one of claims 1 to 5.

21. A method for treating and / or preventing a coronavirus infection and / or suppressing its severity, comprising administering to a subject at least one active ingredient selected from the group consisting of (a) to (e) below: (a) one or more peptides according to any one of claims 1 to 5; (b) one or more polynucleotides encoding the peptide of any one of claims 1 to 5 in an expressible form; (c) an antigen-presenting cell (APC) that presents a complex of a peptide according to any one of claims 1 to 5 and an HLA antigen on its cell surface; (d) an exosome that presents a complex of the peptide according to any one of claims 1 to 5 and an HLA antigen on its cell surface; and (e) A CTL that targets the peptide according to any one of claims 1 to 5.

22. An antibody that binds to the peptide of any one of claims 1 to 5.

23. A method for screening a peptide having CTL inducibility, comprising the steps of: (a) generating candidate sequences consisting of amino acid sequences in which one, two or several amino acid residues have been substituted, deleted, inserted and / or added to an original amino acid sequence consisting of an amino acid sequence selected from among SEQ ID NOs: 3, 12, 1, 2, 4, 5, 7, 9, 10, 11, 13, 14 and 15; (b) selecting a candidate sequence from the candidate sequences generated in (a) that does not have significant homology (sequence identity) with any known human gene product; (c) contacting a peptide consisting of the candidate sequence selected in (b) with an APC; (d) contacting the APCs of (c) with CD8 positive T cells; and (e) selecting a peptide having the same or higher CTL inducibility as the peptide consisting of the original amino acid sequence.

24. 6. An emulsion comprising one or more peptides according to any one of claims 1 to 5, a water-soluble carrier, and an oil-based adjuvant.

25. A kit comprising a container containing the composition according to any one of claims 7 to 13, and a container containing an adjuvant.

26. A T cell receptor alpha chain comprising a CDR3 defined by any amino acid sequence selected from the group consisting of SEQ ID NOs: 32, 34, 36 and 38, or a CDR3 functionally equivalent thereto.

27. A T cell receptor beta chain comprising a CDR3 defined by any amino acid sequence selected from the group consisting of SEQ ID NOs: 33, 35, 37 and 39, or a CDR3 functionally equivalent thereto.

28. A T cell receptor consisting of a combination of any T cell receptor alpha chain described in claim 26 and any T cell receptor beta chain described in claim 27.

29. The T cell receptor according to claim 28, wherein the amino acid sequences of the CDR3 of the T cell receptor α chain and the T cell receptor β chain are any of the following combinations: CDR3 of the T cell receptor α chain CDR3 of the T cell receptor β chain SEQ ID NO: 32 SEQ ID NO: 33, SEQ ID NO: 34 SEQ ID NO: 35, SEQ ID NO:36 SEQ ID NO:37, and Sequence number: 38 Sequence number:

39.

30. A polynucleotide encoding any one of the T cell receptor alpha chains described in claim 26 and any one of the T cell receptor beta chains described in claim 26.

31. A TCR that recognizes any of the peptides described in claims 1-5 presented on an APC by an HLA antigen.

32. A method for determining SARS-CoV-2 infection history, including the following steps: (a) extracting gDNA from PBMCs derived from a subject, or synthesizing cDNA using RNA extracted from PBMCs as a template; (b) comprehensively deciphering the TCRα gene sequence and the TCRβ gene sequence from gDNA or cDNA by NGS (next-generation sequencer) to determine the TCR repertoire; and (c) Profiling the TCR repertoire using SARS-CoV-2-derived peptide-reactive TCRs as an indicator to evaluate the presence of SARS-CoV-2-specific T cells induced by the infection.

33. The method of claim 32, wherein the SARS-CoV-2-derived peptide-reactive TCR is the TCR of claim 31.

34. 34. The method of claim 33, wherein the TCR comprises an amino acid sequence selected from the group consisting of SEQ ID NOs: 32-39.