17 results about "Attenuated vaccine" patented technology

The application discloses a PEDV chimeric virus attenuation identification method based on reverse genetic operation and application of screening potential attenuated vaccine, and the PEDV chimeric virus CHM2013-SP BJ , CHM2013- BJ , CHM2013-SP BJ -ORF3 CHM , CHM2013-SP BJ -E CHM , CHM2013-SP BJ -M CHM , CHM2013-SP BJ -N CHM and CHM2013-(S+ORF3) BJ are constructed and rescued, loss-of-function test and gain-of-function test are carried out, and the attenuated chimeric virus CHM2013-SP BJ -ORF3 CHM and CHM2013-SP BJ -M CHM are obtained, and it is disclosed that the S gene of the PEDV variant BJ2011C promotes virus pathogenicity in cooperation with the ORF3, E and M genes, and the ORF3 gene is the most critical.

This invention discloses a candidate strain of *R. anatipestifer* double-gene deletion attenuated vaccine, its construction method, and its application. The candidate strain of *R. anatipestifer* double-gene deletion attenuated vaccine is *R. anatipestifer* strain CH-1. B739_RS01935-B739_RS07625 A candidate attenuated live vaccine strain with double gene deletion, deposited at the China Center for Type Culture Collection (CCTCC) on May 22, 2025, with accession number CCTCC NO: M20251080, at Wuhan University, Wuhan, China, has been deposited on that date. The attenuated live strain constructed in this invention showed no significant impact on the weight gain of ducklings after immunization, demonstrating good safety. Furthermore, the protection rate against challenge with the wild-type virulent RACH-1 strain reached 83.3% after immunization, indicating excellent immunoprotective efficacy.

This invention provides a live attenuated Brucella vaccine strain M5Δ pyrE Its construction methods and applications belong to the field of biotechnology. The M5... pyrE The strain was obtained by knocking out Brucella mesenteriae strain M5. pyrE Genetically constructed and deposited at the China Center for Type Culture Collection. This invention discovers that... pyrE The gene is associated with Brucella virulence; knocking out this gene significantly weakens Brucella virulence and reduces its intracellular and mouse viability. Compared to the existing vaccine strain M5-9026, M5... pyrE The strain exhibits superior immunoprotective effects, effectively inducing humoral and Th1 cellular immune responses, and demonstrates good safety. The M5 strain constructed in this invention... pyrE This strain has promising potential as a candidate strain for a live attenuated vaccine to prevent brucellosis in animals.

This invention relates to the field of biotechnology, and more particularly to a mutant of the Rift Valley fever virus L protein and its applications. The amino acid sequence of the mutant is based on the amino acid sequence shown in SEQ ID NO:1, with mutations made at position 1189 (aspartic acid) and / or position 1205 (tryptophan). Through cryo-electron microscopy structural analysis and in vitro mismatch experiments, this invention has confirmed that both identified key amino acid sites are involved in regulating the synthetic fidelity of viral polymerase: mutation at N1189 decreases the synthetic fidelity of the polymerase, while mutation at W1205 increases it. This invention not only provides a new target for the development of attenuated vaccines but also provides crucial evidence for elucidating the molecular regulatory mechanisms of RNA virus fidelity.

The invention relates to a Pseudomonas plecoglossicida pldB gene deletion mutant strain and a preparation method and application thereof, and belongs to the technical field of microorganisms and the field of algae preservation, the pldB gene of the mutant strain is deleted or inactivated, the nucleotide sequence of the pldB gene is shown as SEQ ID NO: 1, and the GenBank accession number of the Pseudomonas plecoglossicida is CP031146.1. The virulence of the mutant strain is obviously reduced compared with that of a wild strain of pseudomonas plecoglossicida; the strain can induce appropriate immune response of a host and up-regulate expression of anti-inflammatory factors, is beneficial to relieving immune pathological injury, has good attenuated live vaccine potential, and provides a brand new vaccine candidate strain for prevention and control of the visceral white-spot disease of the large yellow croaker.

This invention discloses a live attenuated vaccine for the prevention of Toxoplasma gondii infection, the active ingredient of which is the tachyzoite of the Toxoplasma gondii RHΔpCaBp1 gene knockout strain. This invention prepares a live attenuated RHΔpCaBp1 vaccine that can be used to prevent Toxoplasma gondii infection in intermediate hosts. Immunization with this live attenuated vaccine, containing 100 Toxoplasma gondii RHΔpCaBp1 tachyzoites, via intraperitoneal injection, showed safety in mice after three immunizations, and demonstrated 100% protection against low-dose virulent strains (intraperitoneal injection of 100 and 500 RH tachyzoites) in the model intermediate host.

The present invention relates to a novel recombinant antigen protein for Japanese encephalitis and, more specifically, to a recombinant antigen protein for Japanese encephalitis, designed through protein structural stability analysis and introduction of point mutations. It has been identified that a composition comprising the recombinant antigen protein for Japanese encephalitis, according to the present invention, exhibits immunogenicity and protective efficacy against challenge inoculation that are superior to those of an approved live-attenuated vaccine. In particular, it has been experimentally identified that the recombinant antigen protein for Japanese encephalitis, of the present invention, exhibits excellent protective efficacy against Japanese encephalitis virus G5 and other genotypes. Therefore, the recombinant antigen protein for Japanese encephalitis, of the present invention, can be variously used in the field of preventing infection by Japanese encephalitis virus G1 to G5.

This invention discloses the construction of a Toxoplasma gondii progesterone-responsive kinase-deficient strain and its application as a live attenuated vaccine. The Toxoplasma gondii progesterone-responsive kinase-deficient strain is derived from Toxoplasma gondii RHΔ... ku80 As a maternal strain, the gene-editing technology was used to knock out the enzyme encoding progesterone-responsive kinase. prk The gene-deleted strain was named RHΔ ku80 Δ prk Experiments have shown that RHΔ ku80 Δ prk The virulence of the strain was significantly reduced, and immunized mice showed good immunoprotection against acute infection with highly virulent and moderately virulent Toxoplasma gondii strains, and significantly inhibited brain cyst formation in a chronic infection model. Therefore, RHΔ ku80 Δ prk This invention has potential application value as a live attenuated vaccine against Toxoplasma gondii. It has significant application prospects.

This invention provides an attenuated vaccine against Coxsackievirus A6 (CVA6), its preparation method, and its application. By comparing a highly pathogenic clinical isolate (CVA6-HeB) with an attenuated strain (CVA6-TW141), the genetic basis of CVA6 virulence was systematically studied. This invention located the core virulence determinant to the P1 capsid region and identified a key lethal amino acid residue (VP3-238) that significantly weakens viral replication in target tissues. Based on this discovery, this invention designed and validated a candidate attenuated live vaccine with significantly reduced lethality.

The present invention relates to an undirected, constrained and accelerated process for modifying pathogenic bacterial strains to render them non-pathogenic while retaining their immunogenicity and whose phenotype is stable; it also relates to the bacteria thus obtained and to live attenuated vaccines comprising said bacteria.

The application discloses a construction method of a human adenovirus type 4 protein V knockout mutant strain and application thereof, and belongs to the technical field of biotechnology. The application precisely knocks out a protein V coding sequence in a human adenovirus type 4 full-genome infectious clone by means of a Red / ET homologous recombination system combined with a ccdB reverse screening technology, and obtains a recombination plasmid pBR322-Ad4-△V-EGFP which is clear in genetic background and highly homozygous in sequence. After the plasmid is transfected into HEK-293 cells, the human adenovirus type 4 protein V knockout mutant strain obtained exhibits a typical “replication-deficient” phenotype: although a particle containing a viral genome can be packaged, the physical titer (4.76×10 6 copies / μL) of the particle is about one order of magnitude lower than that of a wild type, and the progeny virus completely loses secondary infection ability. Transcriptome analysis reveals that the deletion mutation can specifically down-regulate a host proteasome pathway and activate a natural immune response. The mutant strain is high in safety and strong in immunogenicity, and can be used as an ideal attenuated vaccine carrier or a gene therapy tool.

There has been a need to find an optimal composition to obtain a stable formulation composition of a tetravalent attenuated vaccine (lyophilized formulation) against dengue virus. The present disclosure provides a lyophilized composition containing four types of attenuated dengue virus, the composition further containing D-sorbitol, glycine, and trehalose hydrate.

This invention belongs to the field of biotechnology, and specifically relates to a method for constructing and applying a PEDV Nsp6 attenuated live vaccine mutant strain. Based on previous research on the interaction mechanism between the non-structural protein Nsp6 of the PEDV GDU strain and the innate immune transcription factor IRF3, we identified amino acid regions 220-280 of the Nsp6 protein as the key structural domain mediating this interaction. This invention successfully rescued the recombinant mutant strain rPEDV-ΔNsp6 by directionally knocking out this key structural domain of the Nsp6 protein and using reverse genetics. Compared with the parental strain GDU, the rPEDV-ΔNsp6 strain significantly upregulated the production of type I interferon in IPEC-J2 cells, effectively activating the host's innate immune response, thereby constructing a novel genetically engineered attenuated live vaccine candidate strain with innate immune enhancement function. This candidate strain provides a new technical means and scientific basis for improving the immunoprotective effect of PEDV vaccines and optimizing clinical prevention and control strategies.

This invention discloses a linearized mutant plasmid of Tembusu virus SLII, a recombinant virus, and its applications, belonging to the field of molecular biology. Using the pACNR CQW1-Intron infectious clone as a backbone, the SLII stem-loop structure within the 3′UTR Domain-I region was linearized to construct the SLII linearized mutant infectious clone pACNR-CQW1-SLIILiner, which was then rescued to obtain the recombinant virus CQW1-SLIILiner. This recombinant virus exhibits limited replication capacity at the in vitro cellular level and displays a significantly attenuated phenotype in animal models. It can also induce specific neutralizing antibodies and cellular immune responses, providing significant protection against virulent strains. Therefore, the recombinant virus of this invention possesses advantages such as clear molecular genetic markers, high safety, good immunogenicity, and strong genetic stability, and can be applied to the preparation of live attenuated vaccines or related biological products for the prevention of TMUV infection.

The application discloses a microsporum gene deletion strain of Cryptosporidium parvum with deleted DG9 and / or DG10 genes and application thereof. The microsporum gene deletion strain of Cryptosporidium parvum is obtained by directly knocking out dense granule protein DG9 genes and / or DG10 genes of Cryptosporidium parvum through a gene editing technology. The application discloses the regulation of Cryptosporidium parvum dense granule proteins DG9 and DG10 on the pathogenicity of Cryptosporidium parvum. Research shows that the strain with deleted DG9 or DG10 genes or double gene deletion can reduce the clinical symptoms of infected mice and prolong the survival time of the mice. The virulence of the gene deletion strain is weakened, the worm load in the mice is reduced, and the excretion intensity of oocysts is weakened, so that the gene deletion strain has the advantage of weakened virulence and can be used for developing more attenuated vaccines and therapeutic drugs of Cryptosporidium parvum, thereby laying a solid foundation for the prevention and control of Cryptosporidium parvum.

The application discloses a goose astrovirus weakly virulent vaccine candidate strain (referred to as GAstV-GXNNP120), which has a preservation number of CCTCC No:V202564 and a preservation date of September 17, 2025. Research shows that GAstV-GXNNP120 has the advantages of high virus titer, good immunoprotective effect and long antibody duration. In addition, GAstV-GXNNP120 can also be well adapted to LMH cells, and compared with culturing viruses in goose embryos, the cost of culturing viruses in the passage cells is lower, and the quality between batches is more stable. Therefore, the goose astrovirus weakly virulent vaccine candidate strain of the application can be used for further development of a goose astrovirus attenuated live vaccine, and has important significance for clinical prevention and control of goose astrovirus.

The application discloses an infectious bursal disease virus attenuated vaccine strain and a construction method and application thereof, and belongs to the technical field of biotechnology. The application constructs a gene mutant strain through a gene mutation and an infectious cloning operation method, performs a synonymous mutation (TTCAGA) on a TTTCGT motif of a vp2 gene in an IBDV virus genome, and rescues the mutant strain. Compared with a parent strain, the ability of the mutant strain to induce cell apoptosis in an early infection stage is significantly reduced, and the proliferation of the virus is effectively promoted. After the mutant strain is inoculated into SPF chickens, the pathological changes of bursa of Fabricius of the SPF chickens in an early infection stage are obviously weaker than those of the chickens infected by the parent strain, and the replication ability of the mutant strain in an animal body is significantly higher than that of the parent strain. The IBDV genome mutation site provided by the application has important significance for the development of a candidate vaccine strain.