Anti-meningococcal antibodies for in vitro immunoassay

Abstract

The present disclosure relates to monoclonal antibodies targeting a Neisseria meningitidis serogroup B (MenB) antigen and their use for in vitro assay of the potency of MenB antigen for the manufacture of vaccine for preventing meningococcal infection.

Description

PCT / US25 / 48115 26 September 2025 (26.09.2025)1ANTI-MENINGOCOCCAL ANTIBODIES FOR IN VITRO IMMUNOASSAYTECHNICAL FIELD

[0001] The present disclosure relates to monoclonal antibodies targeting a Neisseria meningitidis serogroup B (MenB) antigen and their use for in vitro assay of the potency of MenB antigen for the manufacture of vaccine for preventing meningococcal infection.BACKGROUND

[0002] Neisseria meningitidis is a gram-negative diplococcus with humans as the sole known natural host. N. meningitidis is a frequent colonizer of the human naso- and oropharynx but can be found in other areas of the body such as the anal mucosa, the conjunctiva and the urogenital tract (Rouphael et al., Methods Mol Biol. 2012;799:1-20; Stephens, Vaccine. 2009;27 Suppl 2:B71-7; Batista et al., Asian Pac J Trop Med. 2017;10(11):1019-29).

[0003] At least 12 different meningococcal serogroups have been classified based on the immunochemistry of the capsular polysaccharides (PS). Some strains are more likely than others to cause infection. Worldwide, most cases of meningococcal disease are caused by serogroups A, B, C, W, X, and Y. Serogroup B is responsible for endemic disease and some outbreaks (Harrison et al., [ed.] Orenstein WA, Offit PA, Edwards KM Plotkin SA. Vaccines. 7. Philadelphia (PA): Elsevier; 2018. p. 619-43; Borrow et al., Expert Rev Vaccines. 2017;16(4):313-28; Harrison et al., Emerg Infect Dis. 2013;19(4):566-73, Pollard, Pediatr Infect Dis J. 2004;23(12 Suppl):S274-9; Kvalsvig et al., J Clin Pathol. 2003;56(6):417-22).

[0004] N. meningitidis serogroup B is a respiratory transmission bacterium (through droplets) that cannot survive in the environment, requiring close and prolonged contact, or direct physical contact (such as a kiss) for effective transmission. The asymptomatic carrier, present among less than 2% of children under 5 years of age and 20%-25% of adolescents and young adults, is the primary element in the pathogen transmission pathway and its maintenance in nature, even during periods of epidemics (Christensen et al., Lancet Infect Dis. 2010;10(12):853-61 ; Batista et al., Asian Pac J Trop Med. 2017;10(11):1019-29).

[0005] Serogroup B is an important cause of endemic disease and is responsible for multiple prolonged epidemics in several industrialized countries (Vuocolo etal., Hum Vaccin Immunother. 2018;14(5):1203-15), including Cuba (Rodriguez et al., Mem Inst Oswaldo Cruz. 1999;94(4):433-40), Norway (Fredriksen et al., NIPH Ann. 1991 ;14(2):67-79;PCT / US25 / 48115 26 September 2025 (26.09.2025)2 discussion -80) and New Zealand (Martin et al., J Infect Dis. 1998;177(2):497-500; Dyet et al., Epidemiol Infect. 2006; 134(2): 377-83). Smaller outbreaks due to a single strain have also been reported in other countries such as France (from 2000-2003) (Grodet et al., Microbiol Infect. 2004;10(9):845-8; Caron et al., Lancet Infect Dis. 2011 ;11(6):455-63) and the United States (from 2013-2017), some of which have been associated with colleges and universities (Folaranmi et al., 2015. MMWR Morb Mortal Wkly Rep. 2015;64(22):608- 12; Atkinson et al., Pharmacotherapy. 2016;36(8):880-92).

[0006] The potency of inactivated or subunit vaccines normally requires an in vivo test for each batch prior to its release for public use. Said in vivo tests may involve an immunisationchallenge test using small rodents (mice or rats) and death / survival ratio, clinical signs or colonisation endpoints. The potency of the vaccine can be expressed relative to a standard preparation with known potency by establishing a dose-response curve. However, such challenge models are not always available. In those cases, potency assays may be limited to the measurement of antibody response after immunisation of test animals. The antibodies’ functionality can then be determined by their ability to neutralise the pathogen in vitro or to their ability to kill bacteria in the presence of complement (such as the serum bactericidal antibody assay, or SBA, for meningococcus). These assays are however cumbersome and require the use of many animals.

[0007] ELISA is a widely accepted technology in industry for quantitation of active ingredients, impurities, and antibody responses to a vaccine, due to high sensitivity, specificity and high throughput. It is a very cost effective and easy-to-use method. This method also allows reduction of animal usage.

[0008] Sandwich ELISA is a type of ELISA commonly used to detect and quantify antigens in immunoassays. The advantage of this technique is its high specificity and high sensitivity. However, its main disadvantage is the potential interaction between the capture and detection antibodies, for instance if they compete for the same epitope or if they bind to epitopes that are too close from each other. Thus, there is still a need for further and improved in vitro assays for assessing the potency of MenB antigen used for the manufacture of meningococcal vaccines.

[0009] The inventors have developed an ELISA assay for analyzing a meningococcal vaccine. The assay uses at least a pair of monoclonal antibodies against a MenB antigen, with at least one of the monoclonal antibodies of the said pairs which can recognize a conformational epitope of the said MenB antigen. Thus, the pair of antibodies according to the disclosure are able to quantitatively measure the concentration of MenB antigens with the right conformation, which allows to distinguish between immunogens that retain thePCT / US25 / 48115 26 September 2025 (26.09.2025)3 relevant epitope (and immunogenicity function) and those that have lost the epitope (e.g. due to denaturation, aggregation or breakdown during storage or by mishandling). All pairs of antibodies disclosed herein have been specifically selected for their ability to bind conformational epitopes of MenB antigens. They also have been specifically selected for their ability to be bactericidal. These functional features due to their structure ensures a high specificity in antigen detection and the recognition of functional antigens in an immunogenic composition.

[0010] The assay according to the disclosure may be used to determine the relative potency of a test vaccine, drug substance or drug product by comparing the results with those obtain using a reference standard vaccine, drug substance or drug product, respectively, of known potency. This assay can thus be used to determine whether a manufactured drug substance can be incorporated in the drug product (i.e. final vaccine), and if a batch of a vaccine is suitable for release to the public. Assays of the disclosure are particularly useful for analyzing vaccines which contain multiple different antigens and / or which contain adsorbed antigen(s) (for instance antigen(s) adsorbed on aluminum adjuvant).SUMMARY

[0011] The present disclosure relates to a pair of monoclonal antibodies targeting a Neisseria meningitidis serogroup B (MenB) antigen, comprising:(a) a first monoclonal antibody against factor H binding protein (fHBP) A protein that comprises a heavy chain variable (VH) domain comprising a H-CDR1 of sequence SEQ ID NO: 1 , a H-CDR2 of sequence SEQ ID NO: 2, and a H-CDR3 of sequence SEQ ID NO: 3; and a light chain variable (VL) domain comprising a L-CDR1 of SEQ ID NO: 4, a L-CDR2 of SEQ ID NO: 5 and a L-CDR3 of SEQ ID NO: 6; and(b) a second monoclonal antibody against fHBP A protein that comprises a VH domain comprising a H-CDR1 of sequence SEQ ID NO: 7, a H-CDR2 of sequence SEQ ID NO: 8, and a H-CDR3 of sequence SEQ ID NO: 9; and a VL domain comprising a L-CDR1 of sequence SEQ ID NO: 10, a L-CDR2 of sequence SEQ ID NO: 11 and a L-CDR3 of sequence SEQ ID NO: 12.

[0012] The present disclosure relates to a pair of monoclonal antibodies targeting a Neisseria meningitidis serogroup B (MenB) antigen, comprising:(a) a first monoclonal antibody against factor H binding protein (fHBP) B protein that comprises a heavy chain variable (VH) domain comprising a H-CDR1 of sequence SEQ ID NO: 13, a H-CDR2 of sequence SEQ ID NO: 14, and a H-CDR3 of sequence SEQ ID NO: 15; and a light chain variable (VL) domain comprising a L-CDR1 ofPCT / US25 / 48115 26 September 2025 (26.09.2025)4 sequence SEQ ID NO: 16, a L-CDR2 of sequence SEQ ID NO: 17 and a L-CDR3 of sequence SEQ ID NO: 18; and(b) a second monoclonal antibody against fHBP B protein that comprises a VH domain comprising a H-CDR1 of sequence SEQ ID NO: 19, a H-CDR2 of sequence SEQ ID NO: 20, and a H-CDR3 of sequence SEQ ID NO: 21 ; and a VL domain comprising a L-CDR1 of sequence SEQ ID NO: 22, a L-CDR2 of sequence SEQ ID NO: 23 and a L-CDR3 of sequence SEQ ID NO: 24.

[0013] The present disclosure relates to a pair of monoclonal antibodies targeting a Neisseria meningitidis serogroup B (MenB) antigen, comprising:(a) a first antibody against Neisseria adhesin A (NadA) protein that comprises a heavy chain variable (VH) domain comprising a H-CDR1 of sequence SEQ ID NO: 25, a H-CDR2 of sequence SEQ ID NO: 26, and a H-CDR3 of sequence SEQ ID NO: 27; and a light chain variable (VL) domain comprising a L-CDR1 of sequence SEQ ID NO: 28, a L-CDR2 of sequence SEQ ID NO: 29 and a L-CDR3 of sequence SEQ ID NO: 30; and(b) a second antibody against NadA protein that comprises a VH domain comprising a H-CDR1 of sequence SEQ ID NO: 31 , a H-CDR2 of sequence SEQ ID NO: 32, and a H-CDR3 of sequence SEQ ID NO: 33 ; and a VL domain comprising a L-CDR1 of sequence SEQ ID NO: 34, a L-CDR2 of sequence SEQ ID NO: 35 and a L-CDR3 of sequence SEQ ID NO: 36.

[0014] In some embodiments, said first monoclonal antibody against fHBP A protein comprises a VH domain that has at least 70% sequence identity with SEQ I D NO: 37, and / or a VL domain that has at least 70% sequence identity with SEQ ID NO: 38; and / or wherein said second monoclonal antibody against fHBP A protein comprises a VH domain that has at least 70% sequence identity with SEQ ID NO: 39, and / or a VL domain that has at least 70% sequence identity with SEQ ID NO: 40.

[0015] In some embodiments, said first monoclonal antibody against fHBP B protein comprises a VH domain that has at least 70% sequence identity with SEQ ID NO: 41 , and / or a VL domain that has at least 70% sequence identity with SEQ ID NO: 42; and / or wherein said second monoclonal antibody against fHBP B protein comprises a VH domain that has at least 70% sequence identity with SEQ ID NO: 43, and / or a VL domain that has at least 70% sequence identity with SEQ ID NO: 44.

[0016] In some embodiments, said first monoclonal antibody against NadA protein comprises a VH domain that has at least 70% sequence identity with SEQ I D NO: 45, and / or a VL domain that has at least 70% sequence identity with SEQ ID NO: 46; and / or whereinPCT / US25 / 48115 26 September 2025 (26.09.2025)5 said second monoclonal antibody against NadA protein comprises a VH domain that has at least 70% sequence identity with SEQ ID NO: 47, and / or a VL domain that has at least 70% sequence identity with SEQ ID NO: 48.

[0017] In some embodiments, the pair of monoclonal antibodies targets a factor H binding protein (fHBP) A protein. In one embodiment, the pair of monoclonal antibodies targets fHBP A05. In particular, the pair of monoclonal antibodies targets fHBP A05tmN.

[0018] In some embodiments, the pair of monoclonal antibodies targets a factor H binding protein (fHBP) B protein. In one embodiment, the pair of monoclonal antibodies targets fHBP B01.ln particular, the pair of monoclonal antibodies targets fHBP B01smN.

[0019] In some embodiments, the pair of monoclonal antibodies targets a Neisseria adhesin A (NadA) protein. In one embodiment, the pair of monoclonal antibodies targets NadA1. In particular, the pair of monoclonal antibodies targets a truncated NadA1.

[0020] In the pair of monoclonal antibodies against a MenB antigen according to the disclosure, at least one of the monoclonal antibodies of the said pair recognizes a conformational epitope of the said MenB antigen. In particular, at least the second monoclonal antibody of the pair or the detection antibody recognizes a conformational epitope. Typically, each of the second monoclonal antibody of the pairs of monoclonal antibodies according to the disclosure recognizes a conformational epitope of the MenB antigen. The first monoclonal antibody of the pair recognizes a first epitope of the MenB antigen and the second monoclonal antibody of the pair recognizes a second epitope of the same MenB antigen. First and second epitopes are different epitopes of the same MenB antigen.

[0021] In some embodiments, each of the monoclonal antibodies of the pair of monoclonal antibodies targets a conformational epitope of the MenB antigen. In some embodiments, each of the monoclonal antibodies of the pair targets a conformational epitope of fHBP A, in particular of fHBP A05 or fHBP A05tmN. In some embodiments, each of the monoclonal antibodies of the pair targets a conformational epitope of NadA, in particular of NadA1 or truncated NadA1. In all these embodiments, the first monoclonal antibody of the pair recognizes a first conformational epitope of the MenB antigen and the second monoclonal antibody of the pair recognizes a second conformational epitope of the same MenB antigen. First and second conformational epitopes are different conformational epitopes of the same MenB antigen.

[0022] In the pair of monoclonal antibodies against a MenB antigen according to the disclosure, at least one of the monoclonal antibodies of said pair is bactericidal. ThisPCT / US25 / 48115 26 September 2025 (26.09.2025)6 bactericidal functional feature is the ability of the antibody to lyse and kill in the presence of complement Neisseria meningitidis serogroup B bacteria expressing said MenB antigen (and can be measured by a method such as the serum bactericidal antibody assay, or SBA). The source of complement may be veal complement. Preferably at least one of the monoclonal antibodies of said pair is bactericidal alone. Each monoclonal antibody of said pair may be bactericidal alone.

[0023] In the pair of monoclonal antibodies against a MenB antigen according to the disclosure, at least one of the monoclonal antibodies of said pair recognizes a conformational epitope of the MenB antigen and is bactericidal. Both monoclonal antibodies against a MenB antigen of said pair according to the disclosure may recognize a conformational epitope of the MenB antigen and be bactericidal. When only one monoclonal antibody of said pair recognizes a conformational epitope of the MenB antigen and is bactericidal, the other monoclonal antibody of said pair recognizes a conformational epitope of the MenB antigen or is bactericidal.

[0024] The present disclosure also relates to the use of a pair of monoclonal antibodies according to the disclosure to detect a MenB antigen in a test sample.

[0025] In some embodiments, the MenB antigen is detected by enzyme-linked immunosorbent assay (ELISA), wherein said first monoclonal antibody is a capture antibody; and wherein said second monoclonal antibody is a detection antibody.

[0026] The present disclosure further relates to a method for detecting a Neisseria meningitidis serogroup B (MenB) antigen in a test sample comprising:(a) contacting the test sample with a first monoclonal antibody of a pair of monoclonal antibodies according to the disclosure, wherein said first monoclonal antibody is a capture antibody and is immobilized to a solid support;(b) contacting complexes formed by the capture antibody and MenB antigen present in the test sample with a second monoclonal antibody of said pair of monoclonal antibodies according to the disclosure, wherein said second monoclonal antibody is a detection antibody;(c) detecting the presence, or absence, of MenB antigen bound to the capture antibody using a detection means for the detection antibody.

[0027] The present disclosure further relates to a method for quantifying a Neisseria meningitidis serogroup B (MenB) antigen in a test sample comprising:PCT / US25 / 48115 26 September 2025 (26.09.2025)7(a) contacting the test sample with a first monoclonal antibody of a pair of monoclonal antibodies according to the disclosure, wherein said first monoclonal antibody is a capture antibody and is immobilized to a solid support;(b) contacting complexes formed by the capture antibody and MenB antigen present in the test sample with a second monoclonal antibody of said pair of monoclonal antibodies according to the disclosure, wherein said second monoclonal antibody is a detection antibody;(c) measuring the quantity of MenB antigen bound to the capture antibody using a detection means for the detection antibody.

[0028] In some embodiments, at least one antibody of the pair of monoclonal antibodies recognizes a conformational epitope. In some embodiments, the detection antibody recognizes a conformational epitope. In some embodiments, both antibodies of the pair of monoclonal antibodies recognize a conformational epitope.

[0029] In some embodiments, the measurement in step c) quantitatively indicates the concentration of the detection antibody’s target epitope in the test sample. In some embodiments, the measurement in step c) quantitatively indicates the concentration of the MenB antigen(s) that retain the detection antibody’s target conformational epitope in the test sample. The MenB antigen(s) may be adsorbed on aluminum adjuvant (for instance in a drug product or vaccine), or not adsorbed on aluminum adjuvant (for instance in a drug substance).

[0030] In some embodiments, the presence or quantity of MenB antigen is determined by sandwich ELISA.

[0031] In some embodiments, the MenB antigen is selected from the group consisting of a factor H binding protein (fHBP) A protein, a fHBP B protein, and a Neisseria adhesin A (NadA) protein.

[0032] In some embodiments, the MenB antigen is selected from fHBP A05, fHBP B01 , and NadAl .ln some embodiments, the MenB antigen is selected from fHBP A05tmN, fHBP B01smN, and truncated NadA1.

[0033] Said MenB antigen may be adsorbed on aluminum adjuvant (for instance in a DP or vaccine) or not adsorbed on aluminum adjuvant (for instance in a DS).

[0034] The present disclosure further relates to a method for in vitro analysis of a test sample of an immunogenic composition which comprises at least one Neisseria meningitidis serogroup B (MenB) antigen, comprising:PCT / US25 / 48115 26 September 2025 (26.09.2025)8(a) performing the method for quantifying a MenB antigen according to the disclosure on the test sample and, optionally, on at least one dilution of the test sample;(b) performing the method for quantifying the MenB antigen according to the disclosure on a standard immunogenic composition sample of known potency and, optionally, on at least one dilution of the standard sample; and(c) comparing the results from steps (a) and (b) to determine the relative potency of the at least one MenB antigen in the test immunogenic composition compared to the potency of said at least one MenB antigen in the standard immunogenic composition.

[0035] The present disclosure further relates to a method for manufacturing a vaccine which comprises at least one Neisseria meningitidis serogroup B (MenB) antigen, comprising:(a) Preparing an immunogenic composition comprising at least one MenB antigen selected from the group consisting of a factor H binding protein (fHBP) A protein, a fHBP B protein, and Neisseria adhesin A (NadA) protein;(b) assaying the relative potency of said at least one MenB antigen in at least one test sample of the immunogenic composition by the above method for in vitro analysis; and(c) releasing the immunogenic composition for further manufacture step or for in vivo use if the results of step (b) indicate an acceptable relative potency.BRIEF DESCRIPTION OF THE FIGURES

[0036] Figure 1: Characterization of fHBP A05 specific monoclonal antibodies (mAbs) binning.

[0037] Figure 2: Serum bactericidal activity (SBA) of individual or combinations of fHBP A05 specific mAbs using Veal Complement.

[0038] Figure 3: Stability indication of fHBP A05 specific mAbs.

[0039] Figure 4: Dot blots (detection with 8 anti-A05 mAbs and JAR13).

[0040] Figure 5: Epitope screening of A05tmN against fHBP A05 1-2.1.6 (indicated as 1-2 on the figure) monoclonal antibody (mAb).

[0041] Figure 6: Epitope screening of A05tmN against fHBP A05 1-8.2.2 (indicated as 1-8 on the figure) mAb.

[0042] Figure 7: Specificity assessment of the fHBP A05 DS antigenicity ELISA. A) is specificity assessed using fHBP B01smN, or NadA or dOMV DS, or E.coli lysate. B) is specificity assessed using fHBP A05tmN DS buffer.

[0043] Figure 8: Characterization of fHBP B01 specific mAbs binning.PCT / US25 / 48115 26 September 2025 (26.09.2025)9

[0044] Figure 9: Epitope screening of B01smN against fHBP B01 2-13.1.5 (indicated as 2- 13 on the figure) mAb.

[0045] Figure 10: Epitope screening of B01smN against fHBP B01 1-3.2.3 (indicated as 1- 3 on the figure) mAb.

[0046] Figure 11: Specificity assessment of the fHBP B01 DS antigenicity ELISA

[0047] Figure 12: NadA1 epitope mapping and binning of tested mAbs.

[0048] Figure 13: Optical Density (OD) values of 10 anti-NadA1 mAbs using either NadA1 protein drug product (DP) or NadA1-dOMV drug product as direct coating reagent in ELISA.

[0049] Figure 14: Specificity assessment of A05 antigenicity ELISA in MenB DP (A) and MenPenta DP (B) represented as Iog10 transformed OD values.

[0050] Figure 15: Stability indicating ability of A05 antigenicity ELISA for MenB DP (A) and MenPenta DP (B).

[0051] Figure 16: Specificity assessment of B01 antigenicity ELISA in MenB DP (A) and MenPenta DP (B) represented as Iog10 transformed OD values.

[0052] Figure 17: Stability indicating ability of B01 antigenicity ELISA for MenB DP (A) and MenPenta DP (B).

[0053] Figure 18: Specificity assessment of NadA antigenicity ELISA in MenB DP (A) and MenPenta DP (B).

[0054] Figure 19. Stability indicating ability of NadA antigenicity ELISA for MenB DP (A) and MenPenta DP (B).DESCRIPTION OF THE SEQUENCES

[0055] SEQ ID NO: 1 represents the H-CDR1 of the antibody 1-2.1.6 targeting fHBP A05: SFWLN.

[0056] SEQ ID NO: 2 represents the H-CDR2 of the antibody 1-2.1.6 targeting fHBP A05: DIYPGSGSTNYNEKFRS.

[0057] SEQ ID NO: 3 represents the H-CDR3 of the antibody 1-2.1.6 targeting fHBP A05: AGNDYDHYAMDY.

[0058] SEQ ID NO: 4 represents the L-CDR1 of the antibody 1-2.1.6 targeting fHBP A05: KASQSVNNDVA.

[0059] SEQ ID NO: 5 represents the L-CDR2 of the antibody 1-2.1.6 targeting fHBP A05: FASNRYT.

[0060] SEQ ID NO: 6 represents the L-CDR3 of the antibody 1-2.1.6 targeting fHBP A05: QQDYRSPWT.

[0061] SEQ ID NO: 7 represents the H-CDR1 of the antibody 1-8.2.2 targeting fHBP A05: NYLIE.PCT / US25 / 48115 26 September 2025 (26.09.2025)10

[0062] SEQ ID NO: 8 represents the H-CDR2 of the antibody 1 -8.2.2 targeting fHBP A05: VINPGSGGTNYNEKFKG.

[0063] SEQ ID NO: 9 represents the H-CDR3 of the antibody 1 -8.2.2 targeting fHBP A05: RRGGGFFDY.

[0064] SEQ ID NO: 10 represents the L-CDR1 of the antibody 1-8.2.2 targeting fHBP A05: RANGNIHNYLA.

[0065] SEQ ID NO: 11 represents the L-CDR2 of the antibody 1-8.2.2 targeting fHBP A05: YAKTLAD.

[0066] SEQ ID NO: 12 represents the L-CDR3 of the antibody 1-8.2.2 targeting fHBP A05: QHFWTTPFT.

[0067] SEQ ID NO: 13 represents the H-CDR1 of the antibody 1-3.2.3 targeting fHBP B01 : SYGLH.

[0068] SEQ ID NO: 14 represents the H-CDR2 of the antibody 1-3.2.3 targeting fHBP B01 : VIWAGGSTNYNSALMS.

[0069] SEQ ID NO: 15 represents the H-CDR3 of the antibody 1-3.2.3 targeting fHBP B01 : GIGTGFAY.

[0070] SEQ ID NO: 16 represents the L-CDR1 of the antibody 1-3.2.3 targeting fHBP B01 : RASQSIGTSIH.

[0071] SEQ ID NO: 17 represents the L-CDR2 of the antibody 1-3.2.3 targeting fHBP B01 : YASDSIS.

[0072] SEQ ID NO: 18 represents the L-CDR3 of the antibody 1-3.2.3 targeting fHBP B01 : QQGNSWPYT.

[0073] SEQ ID NO: 19 represents the H-CDR1 of the antibody 2-13.1.5 targeting fHBP B01: SFAMS.

[0074] SEQ ID NO: 20 represents the H-CDR2 of the antibody 2-13.1.5 targeting fHBP B01: SISSGGSTYDPDSVKG.

[0075] SEQ ID NO: 21 represents the H-CDR3 of the antibody 2-13.1.5 targeting fHBP B01: GGNDYIYWYFDV.

[0076] SEQ ID NO: 22 represents the L-CDR1 of the antibody 2-13.1.5 targeting fHBP B01 : RASQSISNNLH.

[0077] SEQ ID NO: 23 represents the L-CDR2 of the antibody 2-13.1.5 targeting fHBP B01 : YASQSIS.

[0078] SEQ ID NO: 24 represents the L-CDR3 of the antibody 2-13.1.5 targeting fHBP B01 : QQSNSWPYT.

[0079] SEQ ID NO: 25 represents the H-CDR1 of the antibody 2-21.3.4.2 targeting NadA1 : RYWMS.PCT / US25 / 48115 26 September 2025 (26.09.2025)11

[0080] SEQ ID NO: 26 represents the H-CDR2 of the antibody 2-21.3.4.2 targeting NadA1 : EINPDSSTINYTPSLKD.

[0081] SEQ ID NO: 27 represents the H-CDR3 of the antibody 2-21.3.4.2 targeting NadA1 : NYTMDC.

[0082] SEQ ID NO: 28 represents the L-CDR1 of the antibody 2-21.3.4.2 targeting NadA1: KSSQSLLYGSNQKNYLA.

[0083] SEQ ID NO: 29 represents the L-CDR2 of the antibody 2-21.3.4.2 targeting NadA1: WASTRES.

[0084] SEQ ID NO: 30 represents the L-CDR3 of the antibody 2-21.3.4.2 targeting NadA1: QQYYSYPYT.

[0085] SEQ ID NO: 31 represents the H-CDR1 of the antibody 2-6.2.5 targeting NadA1 : DTHMH.

[0086] SEQ ID NO: 32 represents the H-CDR2 of the antibody 2-6.2.5 targeting NadA1 : RIDPANDNPTYDPKFQG.

[0087] SEQ ID NO: 33 represents the H-CDR3 of the antibody 2-6.2.5 targeting NadA1 : ERWSLLGGGMDY.

[0088] SEQ ID NO: 34 represents the L-CDR1 of the antibody 2-6.2.5 targeting NadA1 : KSSQNLLNSANQRNYLA.

[0089] SEQ ID NO: 35 represents the L-CDR2 of the antibody 2-6.2.5 targeting NadA1 : WAYIRES.

[0090] SEQ ID NO: 36 represents the L-CDR3 of the antibody 2-6.2.5 targeting NadA1 : QQYYRLPRT.

[0091] SEQ ID NO: 37 represents the VH domain of the antibody 1-2.1.6 targeting fHBP A05:QVQLQQPGAELVKPGTSVKLSCKASGYNFTSFWLNWMKLRPGQGLEWIADIYPGSGST NYNEKFRSKATLTVDTSSSTAYMQLSSLASEDSALYYCARAGNDYDHYAMDYWGQGTS VSVSS

[0092] SEQ ID NO: 38 represents the VL domain of the antibody 1-2.1.6 targeting fHBP A05:SIVMTQTPKFLLVSAGDRVTITCKASQSVNNDVAWYQQKPGQSPKLLIYFASNRYTGVPD RFTGSGYGTDFTFTI NTVQAEDLAVYFCQQDYRSPWTFGGGTKLEI K.

[0093] SEQ ID NO: 39 represents the VH domain of the antibody 1 -8.2.2 targeting fHBP A05:QVQLQQSGADLVRPGTPVKVSCKASGYVFTNYLIEWVNQRPGQGLEWIGVINPGSGGT NYNEKFKGKAIVTADKSSSTAYMQLSSLTSDDSAVYFCARRRGGGFFDYWGQGTTLTV S.PCT / US25 / 48115 26 September 2025 (26.09.2025)12

[0094] SEQ ID NO: 40 represents the VL domain of the antibody 1 -8.2.2 targeting fHBP A05: DIQMTQSPASLSASVGETVTITCRANGNIHNYLAWYQQKQGKSPQLLVYYAKTLADGVP SRFSGSGSGTQFSLKINSLQPEDFGSYYCQHFWTTPFTFGSGTKLEIK.

[0095] SEQ ID NO: 41 represents the VH domain of the antibody 1-3.2.3 targeting fHBP B01: QVQLKESGPGLVAPSQSLSITCTVSGFSLTSYGLHWVRQPPGKGLEWLGVIWAGGSTN YNSALMSRLSIIKDNSKSQVFLKMNSLQTDDTAMYYCARGIGTGFAYWGQGTLVTVSA.

[0096] SEQ ID NO: 42 represents the VL domain of the antibody 1-3.2.3 targeting fHBP B01:DI LLTQSPAI LSVSPGERVSFSCRASQSIGTSI HWYQQRTNGSPRLLI KYASDSISGI PSRF SGSGSGTDFTLSINSVESEDIADYYCQQGNSWPYTFGGGTKLEIK

[0097] SEQ ID NO: 43 represents the VH domain of the antibody 2-13.1.5 targeting fHBP B01: EVKLVESGGGLEKPGGSLKLSCAASGFVFSSFAMSWVRQTAEKRLEWVASISSGGSTY DPDSVKGRFTISRDNARNILFLQMNSLRAEDTAMYYCARGGNDYIYWYFDVWGAGTTVT VSS.

[0098] SEQ ID NO: 44 represents the VL domain of the antibody 2-13.1.5 targeting fHBP B01: VIVLTQSPATLSVTPGDSVSLSCRASQSISNNLHWYQQKSHESPRLLIKYASQSISGIPSR FSGSGSGTDFTLSI NSVETEDFGMYFCQQSNSWPYTFGGGTKLEI K.

[0099] SEQ ID NO: 45 represents the VH domain of the antibody 2-21.3.4.2 targeting NadA1 : EVKLLESGGGLVQPGGSLKLSCAASGFDFSRYWMSWVRQAPGKGLEWIGEINPDSSTI NYTPSLKDKFIISRDNAKNTLYLQMTKVRSEDTALYYCAGNYTMDCWGQGTSVTVSS

[0100] SEQ ID NO: 46 represents the VL domain of the antibody 2-21.3.4.2 targeting NadA1 : DIVMSQSPSSLAVSVGEKVTLSCKSSQSLLYGSNQKNYLAWYQQKPGQSPKLLIYWAST RESGVPDRFTGSGSGTDFTLTISSVKAEDLAIYYCQQYYSYPYTFGGGTKLEIK.

[0101] SEQ ID NO: 47 represents the VH domain of the antibody 2-6.2.5 targeting NadA1 : EVQLQQSGAEVVKPGASVKLSCTASGFNIKDTHMHWVKQRPEQGLEWIGRIDPANDNP TYDPKFQGKATITADTSSNTAYLQLNSLTSEDTAVYNCARERWSLLGGGMDYWGQGTS VTVSS.

[0102] SEQ ID NO: 48 represents a VL domain of the antibody 2-6.2.5 targeting NadA1 :PCT / US25 / 48115 26 September 2025 (26.09.2025)13DIVMSQFPSSLAVSVGEKVTMSCKSSQNLLNSANQRNYLAWYQQKPGQSPKLLIYWAYI RESGVPDRFTASGSGTDFTLTISSVKAEDLAVYYCQQYYRLPRTFGGGTKLEIK.

[0103] SEQ ID NO: 49 represents fHBP A05 wild-type sequence without the signal peptide responsible for lipidation, as disclosed in SEQ ID NO: 1 of WO 2022178196 A1 with its N-terminal cysteine substituted with a methionine: MSSGSGSGGGGVAADIGTGLADALTAPLDHKDKGLKSLTLEDSISQNGTLTLSAQGAEK TFKVGDKDNSLNTGKLKNDKISRFDFVQKIEVDGQTITLASGEFQIYKQDHSAVVALQIEKI NNPDKIDSLINQRSFLVSGLGGEHTAFNQLPSGKAEYHGKAFSSDDAGGKLTYTIDFAAK QGHGKIEHLKTPEQNVELASAELKADEKSHAVILGDTRYGSEEKGTYHLALFGDRAQEIA GSATVKIREKVHEIGIAGKQ.

[0104] SEQ ID NO:50 represents the fHBP A05tmN sequence as disclosed in SEQ ID NO: 2 of WO 2022178196 A1 (mutated non-lipidated A05 protein comprising mutations G220S, L130R and G133D; numbering is determined with respect to sequence SEQ ID NO: 55 (fHBP B24)) with its N-terminal cysteine substituted with a methionine: MSSGSGSGGGGVAADIGTGLADALTAPLDHKDKGLKSLTLEDSISQNGTLTLSAQGAEK TFKVGDKDNSLNTGKLKNDKISRFDFVQKIEVDGQTITLASGEFQIYKQDHSAVVALQIEKI NNPDKIDSLINQRSFRVSDLGGEHTAFNQLPSGKAEYHGKAFSSDDAGGKLTYTIDFAAK QGHGKIEHLKTPEQNVELASAELKADEKSHAVILGDTRYGSEEKSTYHLALFGDRAQEIA GSATVKIREKVHEIGIAGKQ.

[0105] SEQ ID NO: 51 represents fHBP B01 wild-type sequence without the signal peptide responsible for lipidation, as disclosed in SEQ ID NO: 3 of WO 2022178196 A1 with its N-terminal cysteine substituted with a methionine: MSSGGGGSGGGGVTADIGTGLADALTAPLDHKDKGLKSLTLEDSISQNGTLTLSAQGAE KTYGNGDSLNTGKLKNDKVSRFDFIRQIEVDGQLITLESGEFQVYKQSHSALTALQTEQE QDPEHSEKMVAKRRFRIGDIAGEHTSFDKLPKDVMATYRGTAFGSDDAGGKLTYTIDFA AKQGHGKIEHLKSPELNVDLAVAYIKPDEKHHAVISGSVLYNQDEKGSYSLGIFGEKAQE VAGSAEVETANGIHHIGLAAKQ.

[0106] SEQ ID NO:52 represents the mutated fHBP B01smN sequence as disclosed in SEQ ID NO: 4 of WO 2022178196 A1 (mutated non-lipidated B01 protein comprising mutation H248L; numbering is determined with respect to sequence SEQ ID NO: 55 (fHBP B24)) with its N-terminal cysteine substituted with a methionine: MSSGGGGSGGGGVTADIGTGLADALTAPLDHKDKGLKSLTLEDSISQNGTLTLSAQGAE KTYGNGDSLNTGKLKNDKVSRFDFIRQIEVDGQLITLESGEFQVYKQSHSALTALQTEQE QDPEHSEKMVAKRRFRIGDIAGEHTSFDKLPKDVMATYRGTAFGSDDAGGKLTYTIDFA AKQGHGKIEHLKSPELNVDLAVAYIKPDEKHHAVISGSVLYNQDEKGSYSLGIFGEKAQE VAGSAEVETANGIHLIGLAAKQ.PCT / US25 / 48115 26 September 2025 (26.09.2025)14

[0107] SEQ ID NO:53 represents the wild-type NadA1 sequence from MenB MC58 strain, as disclosed in SEQ ID NO: 7 of WO 2022178196 A1 :MKHFPSKVLTTAILATFCSGALAATSDDDVKKAATVAIVAAYNNGQEINGFKAGETIYDIGE DGTITQKDATAADVEADDFKGLGLKKVVTNLTKTVNENKQNVDAKVKAAESEIEKLTTKL ADTDAALADTDAALDETTNALNKLGENITTFAEETKTNIVKIDEKLEAVADTVDKHAEAFN DIADSLDETNTKADEAVKTANEAKQTAEETKQNVDAKVKAAETAAGKAEAAAGTANTAA DKAEAVAAKVTDIKADIATNKADIAKNSARIDSLDKNVANLRKETRQGLAEQAALSGLFQP YNVGRFNVTAAVGGYKSESAVAIGTGFRFTENFAAKAGVAVGTSSGSSAAYHVGVNYE W

[0108] SEQ ID NO: 54 represents truncated NadA1 sequence from MenB MC58 strain in which the 23 amino acids of the signal peptide in N-terminus and the last 55 amino acids of the C-terminus have been deleted:MTSDDDVKKAATVAIVAAYNNGQEINGFKAGETIYDIGEDGTITQKDATAADVEADDFKGL GLKKVVTNLTKTVNENKQNVDAKVKAAESEIEKLTTKLADTDAALADTDAALDETTNALNK LGENITTFAEETKTNIVKIDEKLEAVADTVDKHAEAFNDIADSLDETNTKADEAVKTANEAK QTAEETKQNVDAKVKAAETAAGKAEAAAGTANTAADKAEAVAAKVTDIKADIATNKADIA KNSARIDSLDKNVANLRKETRQGLAEQAALSGLFQPYNVG

[0109] SEQ ID NO:55 represents the fHBP B24 wild-type sequence on the basis of which the numbering of the positions of the mutations in A05 and B01 are determined: CSSGGGGVAADIGAGLADALTAPLDHKDKGLQSLTLDQSVRKNEKLKLAAQGAEKTYGN GDSLNTGKLKNDKVSRFDFIRQIEVDGQLITLESGEFQVYKQSHSALTAFQTEQIQDSEH SGKMVAKRQFRIGDIAGEHTSFDKLPEGGRATYRGTAFGSDDAGGKLTYTIDFAAKQGN GKIEHLKSPELNVDLAAADIKPDGKRHAVISGSVLYNQAEKGSYSLGIFGGKAQEVAGSA EVKTVNGIRHIGLAAKQ.DETAILED DESCRIPTION

[0110] The present disclosure relates to monoclonal antibodies targeting a Neisseria meningitidis serogroup B (MenB) antigen and their use for in vitro assay of the potency of MenB antigen for the manufacture of vaccine for preventing meningococcal infection.Definitions

[0111] Unless otherwise defined herein, scientific and technical terms used in connection with the present disclosure shall have the meanings that are commonly understood by those of ordinary skill in the art. Exemplary methods and materials arePCT / US25 / 48115 26 September 2025 (26.09.2025)15 described below, although methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present disclosure. In case of conflict, the present specification, including definitions, will control. Generally, nomenclature used in connection with, and techniques of, cell and tissue culture, molecular biology, virology, immunology, microbiology, genetics, analytical chemistry, synthetic organic chemistry, medicinal and pharmaceutical chemistry, and protein and nucleic acid chemistry and hybridization described herein are those well-known and commonly used in the art. All publications and other references mentioned herein are incorporated by reference in their entirety. Although a number of documents are cited herein, this citation does not constitute an admission that any of these documents forms part of the common general knowledge in the art.

[0112] It must be noted that as used herein and in the appended claims, the singular forms “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “an antigen” includes a plurality of such antigens and reference to “the protein” includes reference to one or more proteins, and so forth.

[0113] Furthermore, "and / or" where used herein is to be taken as specific disclosure of each of the two specified features or components with or without the other. Thus, the term "and / or" as used in a phrase such as "A and / or B" herein is intended to include "A and B," "A or B," "A" (alone), and "B" (alone). Likewise, the term "and / or" as used in a phrase such as "A, B, and / or C" is intended to encompass each of the following aspects: A, B, and C; A, B, or C; A or C; A or B; B or C; A and C; A and B; B and C; A (alone); B (alone); and C (alone).

[0114] The terms “about” or “approximately” as used herein refer to the usual error range for the respective value readily known to the skilled person in this technical field. Reference to “about” a value or parameter herein includes (and describes) embodiments that are directed to that value or parameter per se. In some embodiments, the term “about” refers to ±10%, ±9%, ±8%, ±7%, ±6%, ±5%, ±4%, ±3%, ±2%, ±1 % of a given value. However, whenever the value in question refers to an indivisible object, such as a molecule or other object that would lose its identity once subdivided, then “about” refers to ±1 of the indivisible object.

[0115] It is understood that aspects and embodiments of the present disclosure described herein include “having,” “comprising,” “consisting of,” and “consisting essentially of” aspects and embodiments. The words “have” and “comprise,” or variations such as “has”, “having”, “comprises”, or “comprising”, will be understood to imply the inclusion of the stated element(s) (such as a composition of matter or a method step) butPCT / US25 / 48115 26 September 2025 (26.09.2025)16 not the exclusion of any other elements. The term “consisting of” implies the inclusion of the stated element(s), to the exclusion of any additional elements. The term “consisting essentially of” implies the inclusion of the stated elements, and possibly other element(s) where the other element(s) do not materially affect the basic and novel characteristic(s) of the disclosure. It is understood that the different embodiments of the disclosure using the term “comprising” or equivalent cover the embodiments where this term is replaced with “consisting of” or “consisting essentially of’.

[0116] Within the disclosure, the term “significantly” used with respect to change intends to mean that the observe change is noticeable and / or it has a statistic meaning.

[0117] The terms “elicit an immune response” as used with regard to an antigen, intend to refer to an amount which, when administered to a subject, is effective for eliciting an immune response against the antigen. This amount may vary depending various factors, such as the health or physical condition of the subject, its age, the capacity of the subject's immune system to produce antibodies, the degree of protection desired, the formulation of the composition containing the antigen, the treating doctor's assessment of the medical situation. This amount may be determined by routine methods known to the skilled person. Immune response indicators include but are not limited to: antibody titer or specificity, as detected by an assay such as enzyme-linked immunoassay (ELISA), bactericidal assay, flow cytometry, immunoprecipitation, Ouchterlony immunodiffusion; binding detection assays of, for example, spot, Western blot or antigen arrays; cytotoxicity assays, etc.

[0118] The term “antibody”, as used herein, refers to an immunoglobulin molecule or an antigen-binding portion thereof. The antibody can be polyclonal, monoclonal, recombinant, chimeric, de-immunized or humanized, fully human, non-human, (e.g., murine), or single chain antibody. In some embodiments, the antibody is a monoclonal antibody. In some embodiments, the antibody is an immunoglobulin G1 (lgG1).

[0119] The term “bactericidal” as used herein for an antibody refers to the ability of said antibody to lyse and kill bacteria expressing the antigen that is recognized by said antibody, in the presence of complement. The source of complement may be veal complement. This ability may be measured by a serum bactericidal antibody assay (SBA). The SBA titer can be defined as the minimal antibody concentration yielding more than 50% killing (K50) of bacteria expressing the antigen that is recognized by the antibody when compared to the mean Colony Forming Units (CFU) count of active blanks (bacteria + active complement). In the present disclosure, to be considered as bactericidal, an antibody needs to produce a decrease in CFU count below the K50 threshold.PCT / US25 / 48115 26 September 2025 (26.09.2025)17

[0120] The terms “Complementarity-determining region” or “CDR” refer to short polypeptide sequences within the variable region of both heavy and light chain polypeptides that are primarily responsible for mediating specific antigen recognition. The term “framework region” or “FR” refers to amino acid sequences within the variable region of both heavy and light chain polypeptides that are not CDR sequences, and are primarily responsible for maintaining correct positioning of the CDR sequences to permit antigen binding. Although the framework regions themselves typically do not directly participate in antigen binding, as is known in the art, certain residues within the framework regions of certain antibodies can directly participate in antigen binding or can affect the ability of one or more amino acids in CDRs to interact with antigen.

[0121] The term “antigen” comprises any molecule, for example a peptide, a protein, a polysaccharide or a glycoconjugate, which comprises at least one epitope that will elicit an immune response and / or against which an immune response is directed. For example, an antigen is a molecule which, optionally after processing, induces an immune response, which is for example specific for the antigen or cells expressing the antigen. After processing, an antigen may be presented by MHC molecules and reacts specifically with T lymphocytes (T cells). According to the present disclosure, any suitable antigen may be envisioned which is a candidate for an immune response. An antigen may correspond to or may be derived from a naturally occurring antigen. As used herein, "antigen" is preferably used to refer to a protein molecule or portion thereof which contains one or more epitopes.

[0122] An “epitope” is the part of the antigen that is recognized by antibodies or T cell receptors. Some epitopes are referred to as discontinuous conformational epitope (“conformational epitope”). This means that the amino acids comprising these epitopes are proximal to each other in the three-dimensional structure of the protein but appear distant from each other when one looks strictly at the one-dimensional linear amino acid sequence. Consequently, it is clear that the three-dimensional structure of the protein is extremely important in terms of what the immune system actually sees.

[0123] As used herein, the term “vaccine” is intended to mean an immunogenic composition directed to a pathogen agent which is administered to a subject to induce an immune response with the intent to protect or treat the subject from an illness caused by the pathogen agent. A vaccine as disclosed herein is intended for use as a preventive (prophylactic) vaccine, for administration to a subject prior to infection, with the intent to prevent, or reduce the likelihood of occurrence of, initial (and / or recurrent) infection. As used herein, the term vaccine may designate a drug product (DP). A drug substance (DS) is the unformulated active (immunogenic) substance (e.g. antigen) which may be subsequentlyPCT / US25 / 48115 26 September 2025 (26.09.2025)18 formulated with excipients and optionally combined with one or more other drug substance(s) to produce the drug product. The drug product is the finished dosage form of the product. The drug product contains the drug substance(s) formulated with other ingredients in the finished dosage form ready for marketing. The vaccine, drug substance and drug product described herein are immunogenic compositions.

[0124] The “potency” of biotechnological or biological products is defined in European Medicines Agency’s ICH Q6B (CPMP / ICH / 365 / 96, version of 1stSeptember 1999, https: / / www.ema.europa.eu / en / ich-q6b-specifications-test-procedures-acceptance- criteria-biotechnological-biological-products-scientific-guideline) as the quantitative measure (expressed in units) of the relevant biological activity of the product. The relevant biological activity for an immunogenic composition or a vaccine is antigenicity of its antigen(s) in order to achieve the induction of an adequate immune response in vivo. The potency of an immunogenic composition or a vaccine may thus be determined by the quantitative measure of the antigenicity of its antigen(s).

[0125] As used herein, the term “antigenicity” denotes binding of specific antibodies to an antigen in an immunogenic composition, e.g. in a drug substance and / or drug product, and is used as a measurement of epitope presentation and intactness. Determining potency, or “relative potency” of a vaccine is typically achieved by assessing antigenicity, or relative antigenicity, of the vaccine with respect to one or more antigens contained therein. “Relative antigenicity” measures difference in antigenicity between test samples and a reference standard (antigenicity of the sample relative to the antigenicity of the reference standard, e.g. sample is 1.2-fold more potent than the reference standard). The “reference standard” or “standard” or “standard vaccine” or “standard DS” or “standard DP” or “standard immunogenic composition” has the same composition that the test sample to which it is compared (for instance the standard for a DS sample has the same composition as the DS sample). Such standard is deemed representative of the production process and its antigenicity or potency is known. By “assaying the relative potency”, it is meant a test of the functional integrity of the antigen to ensure that the antigen can elicit an immune response. The method according to the disclosure can provide quantitative information about the amounts of antigens having functional epitopes in an immunogenic composition (like a DS; DP or vaccine). If this amount is compared to the amount in an immunogenic composition of known potency (a standard immunogenic composition), then it is possible to calculate the relative potency of a test immunogenic composition. For assessing relative potency, it is useful to analyze the test immunogenic composition and the standard immunogenic composition at a variety of strengths. A seriesPCT / US25 / 48115 26 September 2025 (26.09.2025)19 of dilutions of the immunogenic compositions can be analyzed. The dilution series can be tested using the assays disclosed herein, in particular the ELISA or sandwich ELISA disclosed herein, to provide a curve (literally or notionally) of binding assay results against dilution. This curve can be compared to a standard curve ( / .e. the same curve, but obtained with the standard immunogenic composition) to determine relative potency. For instance, by plotting the logarithm of the binding titer against the logarithm of dilution for the test and reference standard immunogenic compositions, the horizontal distance between the two parallel regression lines indicates relative potency (no horizontal separation indicating a relative potency of 100% or 1.0). For instance, after manufacture or storage of a batch of an immunogenic composition (such as a DS, DP or vaccine), a test sample from the batch can be tested using the assay of the disclosure, and the results can be compared to those obtained with the relevant standard of known potency. This comparison will reveal whether the new / stored batch (the test sample) is as potent as it should be. If so, the batch can be released for further use; if not, it can be investigated and / or discarded. For instance, the batch can be released for public distribution and in vivo use. Antigenicity results may be reported in Antigenicity Units / mL (AU / mL) based on the antigenicity unitage assigned to the reference standard. For example, 1 AU / mL may be chosen as being equal to 1 pg / mL of the antigen in the reference standard (protein concentration in pg / mL may be determined by RP-LC method or other suitable analytical method). The relative potency is then used to generate an antigenicity value in AU / mL for the tested sample. “Acceptable potency” means a potency within a range defined as suitable for release of the product for next step of manufacture or for in vivo use, for instance on the basis of the lowest potency resulting in clinically effective response.

[0126] As used herein, the term “specificity” denotes the ability to assess unequivocally the analyte in the presence of components that may be expected to be present. Typically, these may include impurities, degradants, matrix, etc.

[0127] As used herein, the term “sensitivity” denotes the lowest detection level or concentration of the target antigen that the assay can measure.

[0128] Furthermore, it is appreciated that certain features of the disclosure, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the disclosure, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination.

[0129] All lists of items, such as, for example, lists of antigens, are intended to and should be interpreted as Markush groups. Thus, all lists can be read and interpreted asPCT / US25 / 48115 26 September 2025 (26.09.2025)20 items “selected from the group consisting of” the list of items “and combinations and mixtures thereof.”Antibodies

[0130] Accordingly, the present disclosure relates to monoclonal antibodies targeting a Neisseria meningitidis serogroup B (MenB) antigen.

[0131] In some embodiments, the present disclosure relates to a monoclonal antibody against fHBP A protein, comprising:(a) a heavy chain variable (VH) domain comprising a H-CDR1 of sequence SEQ ID NO: 1 , a H-CDR2 of sequence SEQ ID NO: 2, and a H-CDR3 of sequence SEQ ID NO: 3; and(b) a light chain variable (VL) domain comprising a L-CDR1 of SEQ ID NO: 4, a L-CDR2 of SEQ ID NO: 5 and a L-CDR3 of SEQ ID NO: 6.

[0132] In some embodiments, said monoclonal antibody against fHBP A protein comprises a VH domain that has at least 70% sequence identity with SEQ ID NO: 37. In some embodiments, said monoclonal antibody against fHBP A protein comprises a VL domain that has at least 70% sequence identity with SEQ ID NO: 38. In some embodiments, said monoclonal antibody against fHBP A protein comprises a VH domain that has at least 70% sequence identity with SEQ ID NO: 37 and a VL domain that has at least 70% sequence identity with SEQ ID NO: 38.

[0133] In some embodiment, said monoclonal antibody is directed against fHBP A05 protein or fHBP A05tmN. In some embodiments, said monoclonal antibody is used as a capture antibody in an immunoassay detecting or quantifying MenB antigen(s), such as an immunoassay including detection or quantification of MenB fHBP A, fHBP A05, or fHBP A05tmN protein. In some embodiments, said monoclonal antibody binds to a conformational epitope of MenB fHBP A, fHBP A05, or fHBP A05tmN protein.

[0134] In some embodiments, the present disclosure relates to a monoclonal antibody against fHBP A protein, comprising:(a) a VH domain comprising a H-CDR1 of sequence SEQ ID NO: 7, a H-CDR2 of sequence SEQ ID NO: 8, and a H-CDR3 of sequence SEQ ID NO: 9; and(b) a VL domain comprising a L-CDR1 of sequence SEQ ID NO: 10, a L-CDR2 of sequence SEQ ID NO: 11 and a L-CDR3 of sequence SEQ ID NO: 12.

[0135] In some embodiments, said monoclonal antibody against fHBP A protein comprises a VH domain that has at least 70% sequence identity with SEQ ID NO: 39. In some embodiments, said monoclonal antibody against fHBP A protein comprises a VLPCT / US25 / 48115 26 September 2025 (26.09.2025)21 domain that has at least 70% sequence identity with SEQ ID NO: 40. In some embodiments, said monoclonal antibody against fHBP A protein comprises a VH domain that has at least 70% sequence identity with SEQ ID NO: 39, and a VL domain that has at least 70% sequence identity with SEQ ID NO: 40.

[0136] In some embodiments, said monoclonal antibody is directed against fHBP A05 protein or fHBP A05tmN. In some embodiments, said monoclonal antibody is used as a detection antibody in an immunoassay detecting or quantifying MenB antigen(s), such as an immunoassay including detection or quantification of MenB fHBP A, fHBP A05, or fHBP A05tmN protein. In some embodiments, said monoclonal antibody binds to a conformational epitope of MenB fHBP A, fHBP A05, or fHBP A05tmN protein.

[0137] In some embodiments, the present disclosure relates to a monoclonal antibody against fHBP B protein, comprising:(a) a heavy chain variable (VH) domain comprising a H-CDR1 of sequence SEQ ID NO: 13, a H-CDR2 of sequence SEQ ID NO: 14, and a H-CDR3 of sequence SEQ ID NO: 15; and(b) a light chain variable (VL) domain comprising a L-CDR1 of sequence SEQ ID NO: 16, a L-CDR2 of sequence SEQ ID NO: 17 and a L-CDR3 of sequence SEQ ID NO: 18.

[0138] In some embodiments, said monoclonal antibody against fHBP B protein comprises a VH domain that has at least 70% sequence identity with SEQ ID NO: 41. In some embodiments, said monoclonal antibody against fHBP B protein comprises a VL domain that has at least 70% sequence identity with SEQ ID NO: 42. In some embodiments, said monoclonal antibody against fHBP B protein comprises a VH domain that has at least 70% sequence identity with SEQ ID NO: 41 SEQ ID NO: 41 , and a VL domain that has at least 70% sequence identity with SEQ ID NO: 42.

[0139] In some embodiments, said monoclonal antibody is directed against fHBP B01 protein or fHBP B01smN. In some embodiments, said monoclonal antibody is used as a capture antibody in an immunoassay detecting or quantifying MenB antigen(s), such as an immunoassay including detection or quantification of fHBP B, fHBP B01 or fHBP B01smN protein. In some embodiments, said monoclonal antibody binds to a conformational epitope of fHBP B, fHBP B01 or fHBP B01smN protein.

[0140] In some embodiments, the present disclosure relates to a monoclonal antibody against fHBP B protein, comprising:PCT / US25 / 48115 26 September 2025 (26.09.2025)22(a) a VH domain comprising a H-CDR1 of sequence SEQ ID NO: 19, a H-CDR2 of sequence SEQ ID NO: 20, and a H-CDR3 of sequence SEQ ID NO: 21 ; and(b) a VL domain comprising a L-CDR1 of sequence SEQ ID NO: 22, a L-CDR2 of sequence SEQ ID NO: 23 and a L-CDR3 of sequence SEQ ID NO: 24.

[0141] In some embodiments, said monoclonal antibody against fHBP B protein comprises a VH domain that has at least 70% sequence identity with SEQ ID NO: 43. In some embodiments, said monoclonal antibody against fHBP B protein comprises a VL domain that has at least 70% sequence identity with SEQ ID NO: 44. In some embodiments, said monoclonal antibody against fHBP B protein comprises a VH domain that has at least 70% sequence identity with SEQ ID NO: 43, and a VL domain that has at least 70% sequence identity with SEQ ID NO: 44.

[0142] In some embodiment, said monoclonal antibody is directed against fHBP B01 protein or fHBP B01smN. In some embodiments, said monoclonal antibody is used as a detection antibody in an immunoassay detecting or quantifying MenB antigen(s), such as an immunoassay including detection or quantification of MenB fHBP B, fHBP B01 or fHBP B01smN protein. In some embodiments, said monoclonal antibody binds to a conformational epitope of fHBP B, fHBP B01 or fHBP B01smN protein.

[0143] In some embodiments, the present disclosure relates to a monoclonal antibody against NadA protein, comprising:(a) a heavy chain variable (VH) domain comprising a H-CDR1 of sequence SEQ ID NO: 25, a H-CDR2 of sequence SEQ ID NO: 26, and a H-CDR3 of sequence SEQ ID NO: 27; and(b) a light chain variable (VL) domain comprising a L-CDR1 of sequence SEQ ID NO: 28, a L-CDR2 of sequence SEQ ID NO: 29 and a L-CDR3 of sequence SEQ ID NO: 30.

[0144] In some embodiments, said monoclonal antibody against NadA protein comprises a VH domain that has at least 70% sequence identity with SEQ ID NO: 45. In some embodiments, said monoclonal antibody against NadA protein comprises a VL domain that has at least 70% sequence identity with SEQ ID NO: 46. In some embodiments, said monoclonal antibody against NadA protein comprises a VH domain that has at least 70% sequence identity with SEQ ID NO: 45, and a VL domain that has at least 70% sequence identity with SEQ ID NO: 46.

[0145] In some embodiments, said monoclonal antibody is directed against NadA1 protein or a truncated NadA1 protein. In some embodiments, said monoclonal antibody isPCT / US25 / 48115 26 September 2025 (26.09.2025)23 used as a capture antibody in an immunoassay detecting or quantifying MenB antigen(s), such as an immunoassay including detection or quantification of MenB NadA, NadA1 or truncated NadA1 protein. In some embodiments, said monoclonal antibody binds to a conformational epitope of MenB NadA, NadA1 or truncated NadA1 protein.

[0146] In some embodiments, the present disclosure relates to a monoclonal antibody against NadA protein, comprising:(a) a VH domain comprising a H-CDR1 of sequence SEQ ID NO: 31 , a H-CDR2 of sequence SEQ ID NO: 32, and a H-CDR3 of sequence SEQ ID NO: 33 ; and(b) a VL domain comprising a L-CDR1 of sequence SEQ ID NO: 34, a L-CDR2 of sequence SEQ ID NO: 35 and a L-CDR3 of sequence SEQ ID NO: 36.

[0147] In some embodiments, said monoclonal antibody against NadA protein comprises a VH domain that has at least 70% sequence identity with SEQ ID NO: 47. In some embodiments, said monoclonal antibody against NadA protein comprises a VL domain that has at least 70% sequence identity with SEQ ID NO: 48. In some embodiments, said monoclonal antibody against NadA protein comprises a VH domain that has at least 70% sequence identity with SEQ ID NO: 47, and a VL domain that has at least 70% sequence identity with SEQ ID NO: 48.

[0148] In some embodiments, said monoclonal antibody is directed against NadA1 protein or truncated NadA1 protein. In some embodiments, said monoclonal antibody is used as a detection antibody in an immunoassay detecting or quantifying MenB antigen(s), such as an immunoassay including detection or quantification of MenB NadA, NadA1 or truncated NadA1 protein. In some embodiments, said monoclonal antibody binds to a conformational epitope of MenB NadA, NadA1 or truncated NadA1 protein.

[0149] The present disclosure also relates to a pair of monoclonal antibodies targeting a Neisseria meningitidis serogroup B (MenB) antigen, comprising:(a) a first monoclonal antibody against fHBP A protein that comprises a heavy chain variable (VH) domain comprising a H-CDR1 of sequence SEQ ID NO: 1, a H-CDR2 of sequence SEQ ID NO: 2, and a H-CDR3 of sequence SEQ ID NO: 3; and a light chain variable (VL) domain comprising a L-CDR1 of SEQ ID NO: 4, a L-CDR2 of SEQ ID NO: 5 and a L-CDR3 of SEQ ID NO: 6; and(b) a second monoclonal antibody against fHBP A protein that comprises a VH domain comprising a H-CDR1 of sequence SEQ ID NO: 7, a H-CDR2 of sequence SEQ ID NO: 8, and a H-CDR3 of sequence SEQ ID NO: 9; and a VL domain comprising a L-CDR1 of sequence SEQ ID NO: 10, a L-CDR2 of sequence SEQ ID NO: 11 and a L-CDR3 of sequence SEQ ID NO: 12.PCT / US25 / 48115 26 September 2025 (26.09.2025)24

[0150] In some embodiments, said pair of monoclonal antibodies targeting a Neisseria meningitidis serogroup B (MenB) antigen comprises :(a) a first monoclonal antibody against fHBP A protein comprising a VH domain that has at least 70% sequence identity with SEQ ID NO: 37, and / or a VL domain that has at least 70% sequence identity with SEQ ID NO: 38; and / or(b) a second monoclonal antibody against fHBP A protein comprising a VH domain that has at least 70% sequence identity with SEQ ID NO: 39, and / or a VL domain that has at least 70% sequence identity with SEQ ID NO: 40.

[0151] In some embodiments, said pair of monoclonal antibodies targeting a Neisseria meningitidis serogroup B (MenB) antigen comprises(a) a first monoclonal antibody against fHBP A protein comprising a VH domain identical to SEQ ID NO: 37, and / or a VL domain identical to with SEQ ID NO: 38; and / or(b) a second monoclonal antibody against fHBP A protein comprising a VH domain identical to SEQ ID NO: 39, and / or a VL domain identical to SEQ ID NO: 40.

[0152] In some embodiments, said pair of monoclonal antibodies is directed against fHBP A05 protein or fHBP A05tmN. In some embodiments, said first monoclonal antibody is used as a capture antibody and said second monoclonal antibody is used as a detection antibody in an immunoassay detecting or quantifying MenB antigen(s), such as an immunoassay including detection or quantification of MenB fHBP A, fHBP A05, or fHBP A05tmN protein. In some embodiments, said pair of monoclonal antibodies detects MenB fHBP A, fHBP A05 or fHBP A05tmN protein that bears a conformational epitope of MenB fHBP A, fHBP A05 or fHBP A05tmN protein. Preferably, at least one of the monoclonal antibodies of said pair recognizes a conformational epitope of MenB fHBP A, fHBP A05 or fHBP A05tmN protein. Typically, the second antibody of said pair recognizes a conformational epitope of MenB fHBP A, fHBP A05 or fHBP A05tmN protein. In some embodiments, the first antibody of said pair recognizes a first conformational epitope of said MenB antigen, and the second antibody of said pair recognizes a second conformational epitope of said MenB antigen. In some embodiments, each antibody of the pair of monoclonal antibodies detects a different conformational epitope of the MenB fHBP A, fHBP A05 or fHBP A05tmN protein.

[0153] In particular embodiments, in said pair of monoclonal antibodies against MenB fHBP A, fHBP A05 or fHBP A05tmN protein, at least one of the monoclonal antibodies is bactericidal. In particular, the detection antibody may be bactericidal alone.PCT / US25 / 48115 26 September 2025 (26.09.2025)25

[0154] In particular embodiments, in said pair of monoclonal antibodies against MenB fHBP A, fHBP A05 orfHBP A05tmN protein, at least one of the monoclonal antibodies recognizes a conformational epitope of MenB fHBP A, fHBP A05 or fHBP A05tmN protein and is bactericidal. More particularly, in said pair of monoclonal antibodies against MenB fHBP A, fHBP A05 or fHBP A05tmN protein, the detection antibody recognizes a conformational epitope of MenB fHBP A, fHBP A05 or fHBP A05tmN protein and is bactericidal.

[0155] In particular embodiments, in said pair of monoclonal antibodies against MenB fHBP A, fHBP A05 or fHBP A05tmN protein, the capture antibody recognizes a first conformational epitope of MenB fHBP A, fHBP A05 or fHBP A05tmN protein and the detection antibody recognizes a second conformational epitope of MenB fHBP A, fHBP A05 or fHBP A05tmN protein and is bactericidal.

[0156] The present disclosure also relates to a pair of monoclonal antibodies targeting a Neisseria meningitidis serogroup B (MenB) antigen, comprising:(a) a first monoclonal antibody against fHBP B protein that comprises a heavy chain variable (VH) domain comprising a H-CDR1 of sequence SEQ ID NO: 13, a H-CDR2 of sequence SEQ ID NO: 14, and a H-CDR3 of sequence SEQ ID NO: 15; and a light chain variable (VL) domain comprising a L-CDR1 of sequence SEQ ID NO: 16, a L-CDR2 of sequence SEQ ID NO: 17 and a L-CDR3 of sequence SEQ ID NO: 18; and(b) a second monoclonal antibody against fHBP B protein that comprises a VH domain comprising a H-CDR1 of sequence SEQ ID NO: 19, a H-CDR2 of sequence SEQ ID NO: 20, and a H-CDR3 of sequence SEQ ID NO: 21 ; and a VL domain comprising a L- CDR1 of sequence SEQ ID NO: 22, a L-CDR2 of sequence SEQ ID NO: 23 and a L-CDR3 of sequence SEQ ID NO: 24.

[0157] In some embodiments, said pair of monoclonal antibodies targeting a Neisseria meningitidis serogroup B (MenB) antigen comprises:(a) a first monoclonal antibody against fHBP B protein comprising a VH domain that has at least 70% sequence identity with SEQ ID NO: 41 , and / or a VL domain that has at least 70% sequence identity with SEQ ID NO: 42; and / or(b) a second monoclonal antibody against fHBP B protein comprising a VH domain that has at least 70% sequence identity with SEQ ID NO: 43, and / or a VL domain that has at least 70% sequence identity with SEQ ID NO: 44.

[0158] In some embodiments, the pair of monoclonal antibodies targeting a Neisseria meningitidis serogroup B (MenB) antigen comprises:PCT / US25 / 48115 26 September 2025 (26.09.2025)26(a) a first monoclonal antibody against fHBP B protein comprising a VH domain identical to SEQ ID NO: 41 , and / or a VL domain identical to SEQ ID NO: 42; and / or(b) a second monoclonal antibody against fHBP B protein comprising a VH identical to SEQ ID NO: 43, and / or a VL domain identical to SEQ ID NO: 44.

[0159] In some embodiments, said pair of monoclonal antibodies is directed against fHBP B01 protein or fHBP B01smN. In some embodiments said first monoclonal antibody is used as a capture antibody and said second monoclonal antibody is used as a detection antibody in an immunoassay detecting or quantifying MenB antigen(s), such as an immunoassay including detection or quantification of MenB fHBP B, fHBP B01 or fHBP B01smN protein. In some embodiments, said pair of monoclonal antibodies detects MenB fHBP B, fHBP B01 or fHBP B01smN protein that bears a conformational epitope of fHBP B, fHBP B01 or fHBP B01smN protein. Preferably, at least one of the monoclonal antibodies of said pair recognizes a conformational epitope of MenB fHBP B, fHBP B01 or fHBP B01smN protein. Typically, the second antibody of said pair recognizes a conformational epitope of MenB fHBP B, fHBP B01 or fHBP B01smN protein. In some embodiments, each antibody of the pair of monoclonal antibodies detects a different conformational epitope of the MenB fHBP B, fHBP B01 or fHBP B01smN protein.

[0160] In particular embodiments, in said pair of monoclonal antibodies, at least one of the monoclonal antibodies is bactericidal. In particular, the detection antibody and / or the capture antibody may be bactericidal alone. Preferably, the two monoclonal antibodies against MenB fHBP B, fHBP B01 or fHBP B01smN protein of said pair are bactericidal.

[0161] In particular embodiments, in said pair of monoclonal antibodies against MenB fHBP B, fHBP B01 or fHBP B01smN protein, at least one of the monoclonal antibodies recognizes a conformational epitope of MenB fHBP B, fHBP B01 or fHBP B01smN protein and is bactericidal. More particularly, in said pair of monoclonal antibodies against MenB fHBP B, fHBP B01 or fHBP B01smN protein, the detection antibody recognizes a conformational epitope of MenB fHBP B, fHBP B01 or fHBP B01smN protein and is bactericidal.

[0162] In particular embodiments, in said pair of monoclonal antibodies against fHBP B, fHBP B01 or fHBP B01smN protein, the capture antibody and the detection antibody are bactericidal.

[0163] The present disclosure also relates to a pair of monoclonal antibodies targeting a Neisseria meningitidis serogroup B (MenB) antigen, comprising:PCT / US25 / 48115 26 September 2025 (26.09.2025)27(a) a first antibody against NadA protein that comprises a heavy chain variable (VH) domain comprising a H-CDR1 of sequence SEQ ID NO: 25, a H-CDR2 of sequence SEQ ID NO: 26, and a H-CDR3 of sequence SEQ ID NO: 27; and a light chain variable (VL) domain comprising a L-CDR1 of sequence SEQ ID NO: 28, a L-CDR2 of sequence SEQ ID NO: 29 and a L-CDR3 of sequence SEQ ID NO: 30; and(b) a second antibody against NadA protein that comprises a VH domain comprising a H-CDR1 of sequence SEQ ID NO: 31 , a H-CDR2 of sequence SEQ ID NO: 32, and a H-CDR3 of sequence SEQ ID NO: 33 ; and a VL domain comprising a L-CDR1 of sequence SEQ ID NO: 34, a L-CDR2 of sequence SEQ ID NO: 35 and a L-CDR3 of sequence SEQ ID NO: 36.

[0164] In some embodiments, the pair of monoclonal antibodies targeting a Neisseria meningitidis serogroup B (MenB) antigen comprises:(a) a first monoclonal antibody against NadA protein comprising a VH domain that has at least 70% sequence identity with SEQ ID NO: 45, and / or a VL domain that has at least 70% sequence identity with SEQ ID NO: 46; and / or(b) a second monoclonal antibody against NadA protein comprising a VH domain that has at least 70% sequence identity with SEQ ID NO: 47, and / or a VL domain that has at least 70% sequence identity with SEQ ID NO: 48.

[0165] In some embodiments, the pair of monoclonal antibodies targeting a Neisseria meningitidis serogroup B (MenB) antigen comprises:(a) a first monoclonal antibody against NadA protein comprising a VH domain identical to SEQ ID NO: 45, and / or a VL domain identical to SEQ ID NO: 46; and / or(b) a second monoclonal antibody against NadA protein comprising a VH domain identical to SEQ ID NO: 47, and / or a VL domain identical to SEQ ID NO: 48.

[0166] In some embodiments, said pair of monoclonal antibodies is directed against NadA1 protein or truncated NadA1 protein. In some embodiments, said first monoclonal antibody is used as a capture antibody, and said second monoclonal antibody protein is used as a detection antibody in an immunoassay detecting or quantifying MenB antigen(s), such as an immunoassay including detection or quantification of MenB NadA, NadA1 or truncated NadA1 protein. In some embodiments, said pair of monoclonal antibodies detects MenB NadA, NadA1 or truncated NadA1 protein that bears a conformational epitope of NadA, NadA1 or truncated NadA1 protein. Preferably, at least one of the monoclonal antibodies of said pair recognizes a conformational epitope of NadA, NadA1 or truncated NadA1 protein. Typically, the second antibody of said pair recognizes a conformational epitope of NadA, NadA1 or truncated NadA1 protein. In some embodiments, the firstPCT / US25 / 48115 26 September 2025 (26.09.2025)28 antibody of said pair recognizes a first conformational epitope of said MenB antigen, and the second antibody of said pair recognizes a second conformational epitope of said MenB antigen. In some embodiments, each antibody of the pair of monoclonal antibodies detects a different conformational epitope of the NadA, NadA1 or truncated NadA1 protein.

[0167] In particular embodiments, in said pair of monoclonal antibodies against MenB NadA, NadA1 or truncated NadA1 protein, at least one of the monoclonal antibodies is bactericidal. In particular, the detection antibody and / or the capture antibody may be bactericidal alone. Preferably, the two monoclonal antibodies against MenB NadA, NadA1 or truncated NadA1 protein of said pair are bactericidal.

[0168] In particular embodiments, in said pair of monoclonal antibodies against NadA, NadA1 or truncated NadA1 protein, the capture antibody and the detection antibody are bactericidal.

[0169] In particular embodiments, in said pair of monoclonal antibodies against MenB NadA, NadA1 or truncated NadA1 protein, at least one of the monoclonal antibodies recognizes a conformational epitope of MenB NadA, NadA1 or truncated NadA1 protein and is bactericidal. More particularly, in said pair of monoclonal antibodies against MenB NadA, NadA1 or truncated NadA1 protein, the detection antibody recognizes a conformational epitope of MenB NadA, NadA1 or truncated NadA1 protein and is bactericidal.

[0170] In particular embodiments, in said pair of monoclonal antibodies against MenB NadA, NadA1 or truncated NadA1 protein, the capture antibody recognizes a first conformational epitope of MenB NadA, NadA1 or truncated NadA1 protein and is bactericidal, and the detection antibody recognizes a second conformational epitope of MenB NadA, NadA1 or truncated NadA1 protein and is bactericidal.

[0171] In some embodiments, said pairs of monoclonal antibodies are provided in a kit. Accordingly, the disclosure further relates to a kit that comprises at least one pair of monoclonal antibodies according to the disclosure. In some embodiments, the kit comprises (i) a pair of monoclonal antibodies targeting MenB fHBP A protein according to the disclosure, and a pair of monoclonal antibodies targeting MenB fHBP B protein according to the disclosure; (ii) a pair of monoclonal antibodies targeting MenB fHBP A protein according to the disclosure, and a pair of monoclonal antibodies targeting MenB NadA protein according to the disclosure; (iii) a pair of monoclonal antibodies targeting MenB fHBP B protein according to the disclosure, and a pair of monoclonal antibodies targeting MenB NadA protein according to the disclosure; or (iv) a pair of monoclonal antibodiesPCT / US25 / 48115 26 September 2025 (26.09.2025)29 targeting MenB fHBP A protein according to the disclosure, a pair of monoclonal antibodies targeting MenB fHBP B protein according to the disclosure, and a pair of monoclonal antibodies targeting MenB NadA protein according to the disclosure.

[0172] Identity (e.g., percent homology) may be determined using various known sequence comparison tools, such as any homology comparison software computing a pairwise sequence alignment, including for example, the Blast software of the National Center of Biotechnology Information (NCBI), such as by using default parameters. The identity is a global identity, i.e., an identity over the entire amino acid or nucleic acid sequences and not over portions thereof. Pairwise global alignment was defined by Needleman et al., Journal of Molecular Biology, 1970, pages 443-53, volume 48). For example, when starting from a polypeptide sequence and comparing to other polypeptide sequences, the EMBOSS-6.0.1 Needleman-Wunsch algorithm (available from http: / / emboss.sourceforge.net / apps / cvs / emboss / apps / needle.html) may be used to find the optimum alignment of two sequences along their entire length - a “Global alignment”.

[0173] By “at least 70% sequence identity”, it is meant any percentage between 70% and 100% (e.g at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, at least 99.5% or more).

[0174] In some embodiments, the monoclonal antibody according to the disclosure is a murine monoclonal antibody. In some embodiments, the monoclonal antibody according to the disclosure is an igG 1 antibody.Antigens

[0175] The monoclonal antibodies according to the disclosure target a Neisseria meningitidis serogroup B (MenB) antigen selected from the group consisting of (i) a factor H binding protein (fHBP) A protein, or one of its variants; (ii) a fHBP B protein, or one of its variants; and (iii) a Neisseria adhesin A (NadA) protein, or one of its variants. In one embodiment, a fHBP A protein is fHBP A05, or fHBP A05tmN. In one embodiment, a fHBP B protein is fHBP B01 or fHBP B01smN. In one embodiment, a NadA protein is NadA1 or truncated NadA1. The fHBP may be lipidated or non-lipidated. In one embodiment, the MenB antigen is a non-lipidated fHBP protein, in particular a non-lipidated fHBP A protein or a non-lipidated fHBP A05 protein, or a non-lipidated fHBP B protein or a non-lipidated fHBP B01 protein, or is fHBP A05tmN or fHBP BOIsmN.The MenB antigen may be adsorbed on aluminum adjuvant (for instance in a DP or vaccine) or not adsorbed on aluminum adjuvant (for instance in a DS).PCT / US25 / 48115 26 September 2025 (26.09.2025)30

[0176] In some embodiments, the monoclonal antibody according to the disclosure targets a conformational epitope of a MenB antigen. In some embodiments, the monoclonal antibody according to the disclosure targets a conformational epitope of fHBP A05. In some embodiments, the conformational epitope of fHBP A05 is comprised in the region defined by amino acids 20 to 41 , 61 to 83 and 178 to 198. In some embodiments, the conformational epitope of fHBP A05 is comprised in the region defined by amino acids 133 to 147 and 213 to 224. In some embodiments, the monoclonal antibody according to the disclosure targets a conformational epitope of fHBP B01. In some embodiments, the conformational epitope of fHBP B01 is comprised in the region defined by amino acids 25 to 41 and 65 to 80. In some embodiments, the monoclonal antibody according to the disclosure targets a conformational epitope of NadA1. In some embodiments, the conformational epitope of truncated NadA1 is comprised in the region defined by amino acids 3-16 or 37-51 of the sequence SEQ ID NO: 54. Epitopes are the parts of an antigen that are recognised by and bind to the antigen binding sites of antibodies. Determining whether an antibody recognizes a conformational epitope is routine in the art, and can be tested against a panel of linear peptide fragments from the target antigen and the binding can be compared to the antibody's binding against the complete antigen. As an alternative, binding can be compared before and after denaturation of the target antigen.

[0177] In some embodiments, the MenB antigen, e.g. fHBP A protein, fHBP B protein, and / or NadA protein, is present in a vaccine or immunogenic composition, e.g. in a drug substance or drug product, intended for the immunization against Neisseria meningitidis, in particular Neisseria meningitidis serogroup B. In some embodiments, the MenB antigen is present in a vaccine or immunogenic composition further comprising a meningococcal serogroup A, serogroup C, serogroup W, serogroup Y, and / or serogroup X antigen. In some embodiments, the MenB antigen is present in a MenABCWY vaccine or immunogenic composition. By MenABCWY vaccine or immunogenic composition, it is meant a vaccine or an immunogenic composition comprising at least one antigen from each of meningococcal serogroup A, serogroup B, serogroup C, serogroup W, and serogroup Y. fHBP

[0178] The meningococcal fHBP also referred to in the art as lipoprotein 2086 (LP2086), ORF2086, Genome-derived Neisserial antigen (GNA) 1870, or “741”, is a lipoprotein expressed at the bacterial surface of almost all invasive meningococcal isolates. fHBP is an important virulence factor as it binds human complement factor H (fH), a negative regulator of the alternative complement pathway (Seib et al., Expert Rev Vaccines.PCT / US25 / 48115 26 September 2025 (26.09.2025)312015;14(6):841-59). The binding of fHBP to human fH enables the pathogen to escape alternative complement-mediated killing by the host innate immune system and to survive in human serum and blood.

[0179] Three major genetic and immunological fHBP variants have been described: variant 1 , corresponding to subfamily B, and variants 2 and 3, both classified in subfamily A (Seib et al., Expert Rev Vaccines. 2015;14(6):841-59). Further to the nomenclature provided by Pfizer (fHBP A and B) and Novartis (variants 1 , 2 and 3), fHBPs are identified in the PubMLST database with a unique ID number. Although there is significant antigenic variability between fHBP subfamilies A and B, protein sequences within a subfamily are highly conserved with > 86% sequence identity, among different strains. The ten most prevalent fHBP variants represented in the MenB strain global population account for approximately 80% of the invasive disease-causing strains in the United States and Europe combined (Bambini et al., Vaccine. 2009;27(21):2794-803; Chang, J Infect 2019; S0163- 4453(19):30272-5; Lucidarme, Clin Vaccine Immunol 2010; 17(6):919-29; and Murphy etal., The Journal of infectious diseases. 2009;200(3):379-89; Wang et al., Vaccine. 2011 ;29(29- 30):4739-44).

[0180] The fHBPs according to the present disclosure may be wild-type (or naturally occurring) polypeptides or may be non-lipidated fHBP and / or modified by amino acid substitutions, insertions, or deletions (non-naturally occurring), provided that the polypeptide can elicit an immune response.

[0181] The fHBPs according to the present disclosure may be lipidated or non- lipidated fHBPs. ORF2086 polypeptide is expressed in N. meningitidis as a precursor protein having a lipoprotein signal motif. During processing, the motif is cleaved to leave an N-terminal cysteine residue that is co-translationally modified with a lipid anchor that tethers the protein to the neisserial outer membrane (McNeil et al. (2013) MMBR 77(2):234-252).

[0182] T o avoid lipidation of a recombinant protein, various techniques known in the art can be used. As example, it may be possible to delete the lipidation peptide signal or to replace the lipidation peptide signal with another peptide signal not recognized by the cells in which the protein is produced. US 10,300,122 B2 describes the use of this technique for ORF 2086.

[0183] It is also possible to either substituting the codon coding for the N-terminal cysteine with a codon coding for another amino acid or to remove the codon coding for the N-terminal cysteine. For example, regarding fHBPs, US 10,300,122 B2 describes the fusion of an ATG (methionine) codon directly to the second 5’ terminal codon of the ORF2086PCT / US25 / 48115 26 September 2025 (26.09.2025)32 coding for the mature polypeptide resulting in deleting the cysteine lipidation site (or substituting the cysteine by the methionine). Also, for example, US 9,724,402 B2 or US 11 ,077,180 B2 disclose the obtaining of non-lipidated fHBP where the N-terminal Cys is substituted with an amino acid that is not a Cys residue.

[0184] The fHBPs according to the present disclosure may be naturally occurring or non-naturally occurring proteins. Non-naturally occurring proteins refers to "man-made proteins" and encompass fHBP with heterologous components that are not found in nature by opposition to naturally occurring proteins. Non-naturally occurring proteins may be chimeric proteins or mutated proteins. “Chimeric proteins” in the context of the present disclosure intends to refer to protein comprising two or more different components, each derived from a different fHBP (e.g., variant 1 , 2, or 3). Mutations in a mutated protein may include amino acid substitution, insertion, or deletion. In one embodiment, a mutation is an amino acid substitution.

[0185] Non-naturally occurring fHBPs that may be included in immunogenic compositions are still able to elicit an immune response against fHBPs. In one embodiment, the non-naturally occurring fHBPs according to the present disclosure may be mutated fHBPs. Mutations, such as amino acids substitutions, may be introduced in order to reduce or suppress the binding of the fHBP antigen to the factor H (fH) of the coagulation normally present in the blood of an individual. The prevention of the binding of fH to the fH BP antigens in the immunogenic compositions of the disclosure therefore may increase the amounts of antigens accessible to the immune system and improve the efficacy and efficiency of the immune response towards those antigens. Advantageously, the mutated fHBP may elicit an anti- fHBP antibody repertoire directed at fHBP epitopes within the fH binding site, which resulted in greater protective complement deposition activity than the antibodies elicited by the wild-type (WT) fHBP antigens, which targeted fHBP epitopes outside of the fH binding site.

[0186] The non-naturally occurring fHBPs may present a reduced affinity towards fH compared to the corresponding naturally occurring fHBP or an improved thermal stability. Affinity towards fH protein and thermal stability may be measured as disclosed in WO 2016 / 014719 A1 (as in Examples 1 or 3 of this document). fHBP A

[0187] In some embodiments, the MenB antigen is a fHBP A protein. The fHBP A protein may be a lipidated or a non-lipidated protein. In one exemplary embodiment, an fHBP A protein may be a non-lipidated protein.PCT / US25 / 48115 26 September 2025 (26.09.2025)33

[0188] In one embodiment, a fHBP A protein may be a naturally or a non-naturally occurring fHBP. In one embodiment, a fHBP A protein may be a naturally occurring fHBP. In another embodiment, a fHBP A protein may be a non-naturally occurring fHBP. In one exemplary embodiment, a fHBP A protein may be a mutated protein. This mutated fHBP A may present a reduced affinity towards fH compared to the corresponding naturally occurring fHBP A and / or an improved thermal stability. In one exemplary embodiment, a fHBP A protein may be a triple mutated non-lipidated (tmN) fHBP A protein.

[0189] In some embodiments, a fHBP A protein may be fHBP A05 of sequence SEQ ID NO: 49. In one exemplary embodiment, a fHBP A protein may be a fHBP A05tmN, in particular a fHBP A05tmN of sequence SEQ ID NO: 50. fHBP B

[0190] In some embodiments, the MenB antigen is a fHBP B protein. The fHBP B protein may be a lipidated or a non-lipidated protein. In one exemplary embodiment, an fHBP B protein may be a non-lipidated protein.

[0191] In one embodiment, a fHBP B protein may be a naturally or a non-naturally occurring fHBP. In one embodiment, a fHBP B protein may be a naturally occurring fHBP. In another embodiment, a fHBP B protein may be a non-naturally occurring fHBP. In one exemplary embodiment, a fHBP B protein may be a mutated protein. This mutated fHBP B may present a reduced affinity towards fH compared to the corresponding naturally occurring fHBP B and / or an improved thermal stability. In one exemplary embodiment, a fHBP B protein may be a single mutated non-lipidated (smN) fHBP B protein.

[0192] In some embodiments, a fHBP B protein may be fHBP B01 of sequence SEQ ID NO: 51. In one exemplary embodiment, a fHBP B protein may be a fHBP B01smN, in particular a fHBP B01smN of sequence SEQ ID NO: 52.NadA

[0193] Neisseria adhesin A (NadA, previously known as GNA1994) is a surface- exposed trimeric protein forming oligomers anchored via a transmembrane domain into the outer membrane and plays a key role in adhesion and invasion to epithelial cells (Capecchi etal., Mol. Microbiol. 2005;55:(687-98)). The sequences of NadA antigen from many strains have been published, and the protein's activity as a Neisserial adhesin has been well documented. The nadA gene is present in approximately 50% of meningococcal isolates.PCT / US25 / 48115 26 September 2025 (26.09.2025)34NadA exhibits growth- phase dependent expression, with maximal levels in the stationary growth phase.

[0194] The NadA antigen was included in the published genome sequence for meningococcal serogroup B strain MC58 as gene NMB1994 (GenBank accession number Gl:7227256).

[0195] A NadA polypeptide according to the present disclosure may be wild-type polypeptide or may be modified by amino acid substitutions, insertions, truncations or deletions, provided that the polypeptide can elicit an immune response against NadA. In some embodiments, a NadA protein to be used may be a N-terminally and / or C-terminally truncated NadA or NadA proteins comprising amino acids deletions or insertions, for example as disclosed in references WO 01 / 64920; WO 01 / 64922; or WO 03 / 020756.

[0196] In one embodiment, a recombinant NadA protein to be detected in an assay as disclosed herein may be a NadA1 variant. NadA1 may be obtained from the NadA sequence of MenB MC58 strain. In one embodiment, NadA1 has a sequence of SEQ ID NO: 53. In one exemplary embodiment, NadA1 is without its C-terminal membrane anchor (deletion of residues 308-362 of SEQ ID NO: 53) with concomitant removal of the 23 amino acids signal peptide (deletion of residues 2 to 24 of SEQ ID NO: 53), to leave a 284 amino acids protein (SEQ ID NO: 54) and is described herein as truncated NadA1.Immunoassay

[0197] The present disclosure also relates to the use of a monoclonal antibody or pair of monoclonal antibodies according to the disclosure to detect a MenB antigen in a test sample. In some embodiments, at least one pair of monoclonal antibodies according to the disclosure is used to quantitatively measure the concentration of a MenB antigen in a test sample. The use of a monoclonal antibody of the disclosure which binds to a conformational epitope allows determining the concentration of the corresponding functional epitope in the vaccine sample, and can distinguish between immunogens or antigens which retain the relevant epitope (and immunogenicity function) and those which have lost the epitope (e.g. due to denaturation, aggregation or breakdown during storage or by mishandling). Detection of a MenB antigen with a monoclonal antibody or pair of monoclonal antibodies according to the disclosure thus enables quantifying the antigenicity of the test sample that contains the MenB antigen and so determining the potency of the test sample.

[0198] In some embodiments, the monoclonal antibody or pair of monoclonal antibodies according to the disclosure targets a Neisseria meningitidis serogroup B (MenB)PCT / US25 / 48115 26 September 2025 (26.09.2025)35 antigen selected from the group consisting of a fHBP A protein, a fHBP B protein, a NadA protein and a variant thereof. In one embodiment, a fHBP A protein may be fHBP A05 or A05tmN. In one embodiment, a fHBP B protein may be fHBP B01 or BOIsmN. In one embodiment, a NadA protein may be NadA1 or truncated NadA1.

[0199] In some embodiments, the MenB antigen is detected by enzyme-linked immunosorbent assay (ELISA), wherein, in the pair of monoclonal antibodies according to the disclosure, said first monoclonal antibody is a capture antibody; and wherein said second monoclonal antibody is a detection antibody.

[0200] In some embodiments, the ELISA is a sandwich ELISA. In this format, the target antigen in the test sample is bound between a capture antibody and a detection antibody. At the beginning of the procedure, the capture antibody is already immobilized on a solid surface, like the well surface of a microtiter plate. The detection antibody is applied as the last step before quantification. The two antibodies in the sandwich ELISA bind to different epitopes (different places) on the target antigen. Moreover, it is very important that the capture antibody and target antibody do not interfere with each other’s binding capabilities.

[0201] In some embodiments, the detection antibody may be labelled to detect a target antigen or quantify its amount. In some embodiments, the detection antibody is labelled with an enzyme, which is then used to catalyze a reaction whose product is readily detectable. The linked enzyme can cause a detectable change in an enzyme substrate which is added to the labelled antibody after it becomes immobilized e.g. to modify a substrate in a manner which causes a color change. For example, the enzyme may be a peroxidase (e.g. horseradish peroxidase, HRP), or a phosphatase (e.g. alkaline phosphatase, AP). Other enzymes can also be used e.g. laccase, B-galactosidase, etc.

[0202] The choice of substrate will depend on the choice of linked enzyme. These parameters are familiar to those skilled in ELISA. Substrates may undergo a colorimetric change, a chemiluminescent change, or a chemifluorescent change when contacted with the linked enzyme. Colorimetric substrates (and their enzymatic partners) include, but are not limited to: PNPP or p-Nitrophenyl Phosphate (AP); ABTS or 2,2'-Azinobis [3- ethylbenzothiazoline-6-sulfonic acid] (HRP); OPD or o-phenylenediamine dihydrochloride (HRP); and TMB or 3,3',5,5"-tetramethylbenzidine (HRP). Chemiluminescent substrates include luminol or 5-amino-2,3-dihydro-1 ,4-phthalazinedione (HRP), particularly in the presence of modified phenols such as p-iodophenol. Chemifluorescent substrates include p-hydroxyhydrocinnamic acid. Various proprietary substrates are also available and thesePCT / US25 / 48115 26 September 2025 (26.09.2025)36 can be used with the disclosure if desired e.g. QuantaBlu, QuantaRed, SuperSignal, Turbo TMB, etc.

[0203] In some embodiments, the detection antibody is directly labelled by conjugation to a label such as a colored particle, an electrochemically active reagent, a redox reagent, a radioactive isotope, a fluorescent label or a luminescent label. In some embodiments, the detection antibody is indirectly labelled and can be conjugated to a high affinity tag such as biotin, avidin or streptavidin. An enzyme conjugated to a ligand for the tag, such as avidin, streptavidin or biotin, can then be used to detect immobilized detection antibody. In some embodiments, the detection antibody is detected by a secondary antibody conjugated to a label; typically the secondary antibody recognizes the host species of the detection antibody (e.g. is the detection antibody is a mouse antibody, the secondary antibody is anti-mouse antibody).

[0204] The present disclosure further relates to a method for detecting a Neisseria meningitidis serogroup B (MenB) antigen in a test sample comprising:(a) contacting the test sample with a (i.e. at least one) first monoclonal antibody of a pair of monoclonal antibodies according to the disclosure, wherein said first monoclonal antibody is a capture antibody and is immobilized to a solid support;(b) contacting complexes formed by the capture antibody(ies) and MenB antigen(s) present in the test sample with a (i.e. at least one) second monoclonal antibody of said pair of monoclonal antibodies according to the disclosure, wherein said second monoclonal antibody is a detection antibody;(c) detecting the presence or absence of MenB antigen(s) bound to the capture antibody(ies) using a detection means for the detection antibody.

[0205] The detection of the presence of MenB antigen(s) is determined by the detection of a signal from the detection antibody.

[0206] The present disclosure also relates to a method for quantifying a Neisseria meningitidis serogroup B (MenB) antigen in a test sample comprising:(a) contacting the test sample with a (i.e. at least one) first monoclonal antibody of a pair of monoclonal antibodies according to the disclosure, wherein said first monoclonal antibody is a capture antibody and is immobilized to a solid support;(b) contacting complexes formed by the capture antibody(ies) and MenB antigen(s) present in the test sample with a (i.e. at least one) second monoclonal antibody of said pair of monoclonal antibodies according to the disclosure, wherein said second monoclonal antibody is a detection antibody;PCT / US25 / 48115 26 September 2025 (26.09.2025)37(c) measuring the quantity of MenB antigen(s) bound to the capture antibody(ies) using a detection means for the detection antibody.

[0207] In some embodiments, at least one antibody of the pair of monoclonal antibodies recognizes a conformational epitope. In some embodiments, the detection antibody recognizes a conformational epitope. In some embodiments, both antibodies of the pair of monoclonal antibodies recognize a conformational epitope. In these embodiments, the first monoclonal antibody of the pair recognizes a first conformational epitope of the MenB antigen and the second monoclonal antibody of the pair recognizes a second conformational epitope of the same MenB antigen. First and second conformational epitopes are different conformational epitopes of the same MenB antigen.

[0208] In some embodiments, the measurement in step c) quantitatively indicates the concentration of the detection antibody’s target epitope in the test sample. In some embodiments, the measurement in step c) quantitatively indicates the concentration of the MenB antigen(s) that retain the detection antibody’s target conformational epitope in the test sample. The MenB antigen(s) may be adsorbed on aluminum adjuvant (for instance in a DP or vaccine) or not adsorbed on aluminum adjuvant (for instance in a DS).

[0209] In some embodiments, the test sample is a vaccine sample. In some embodiments, the test sample is a drug substance (DS) or a drug product (DP). The drug substance is an immunogenic composition comprising the unformulated active ingredient, i.e. an antigen, i.e. a MenB antigen. For instance, the DS comprises a fHBP protein (like a fHBP A05, or a fHBP A05tmN, or a fHBP B01 , or a fHBP B01smN) or a NadA protein (like a NadA1 protein or a truncated version of NadA1 protein). In the DS such antigen is not adsorbed, in particular not adsorbed on aluminum adjuvant. The drug product is an immunogenic composition comprising a drug substance, i.e. a MenB antigen. Said drug product may comprise the MenB antigens after their formulation with aluminum adjuvant and the MenB antigens may be adsorbed on the aluminum adjuvant. Said drug product may be a vaccine.

[0210] Detection means for the detection antibody are well-known in the art and depends on the type of detection antibody, and of whether the antibody is directly or indirectly labelled, as explained above. Detection means typically include, e.g., means for measuring a colorimetric signal, a luminescent signal, a fluorescent signal, a redox potential, or a radioactive signal.

[0211] In some embodiments, the presence or quantity of MenB antigen is determined by sandwich ELISA.PCT / US25 / 48115 26 September 2025 (26.09.2025)38

[0212] In some embodiments, the MenB antigen is selected from the group consisting of a fHBP A protein, a fHBP B protein, and a NadA protein. In some embodiments, the MenB antigen is selected from fHBP A05, fHBP B01 , and NadA1. In some embodiments, the MenB antigen is selected from fHBP A05tmN, fHBP B01smN, and truncated NadA1.

[0213] In some embodiments, at least one MenB antigen is detected or quantified in the test sample. In some embodiments, at least two MenB antigens are detected or quantified in the test sample, e.g. a fHBP A protein and a fHBP B protein; a fHBP A protein and a NadA protein; or a fHBP B protein and a NadA protein. In some embodiments, at least three MenB antigens are detected or quantified in the test sample, e.g. a fHBP A protein, a fHBP B protein, and a NadA protein. In said embodiments, the first and second monoclonal antibodies of the disclosure used in the method are selected based on their specificity for the MenB antigen(s) to be assayed.Potency assay

[0214] Assaying potency of an immunogenic composition, such as a drug substance or drug product, enables determining if antigenicity of an antigen is compromised in the drug substance or drug product, for instance by interaction with other components of the drug product, such as other antigen(s) or adjuvant, or by product degradation. For example, the antigenic site(s) or epitope(s) may be masked by a high affinity physical or chemical association with the adjuvant or other antigens. Determining potency, or relative potency of a vaccine is typically achieved by assessing antigenicity, or relative antigenicity, of the vaccine with respect to one or more antigens contained therein.

[0215] The present disclosure also relates to a method for in vitro analysis of a test sample of an immunogenic composition which comprises at least one Neisseria meningitidis serogroup B (MenB) antigen, comprising:(a) performing the method for quantifying a MenB antigen according to the disclosure on the test sample and, optionally, on at least one dilution of the test sample;(b) performing the method for quantifying the MenB antigen according to the disclosure on a standard immunogenic composition sample of known concentration of said MenB antigen and, optionally, on at least one dilution of the standard sample; and(c) comparing the results from steps (a) and (b) to determine the relative potency of the at least one MenB antigen in the test immunogenic composition compared to the potency of said at least one MenB antigen in the standard immunogenic composition.PCT / US25 / 48115 26 September 2025 (26.09.2025)39

[0216] The present disclosure also relates to a method for in vitro analysis of a test sample of an immunogenic composition which comprises at least one Neisseria meningitidis serogroup B (MenB) antigen, comprising:(a) performing the method for quantifying a MenB antigen according to the disclosure on the test sample and, optionally, on at least one dilution of the test sample;(b) performing the method for quantifying the MenB antigen according to the disclosure on a standard immunogenic composition sample of known potency and, optionally, on at least one dilution of the standard sample; and(c) comparing the results from steps (a) and (b) to determine the relative potency of the at least one MenB antigen in the test immunogenic composition compared to the potency of said at least one MenB antigen in the standard immunogenic composition.

[0217] In some embodiments, the test immunogenic composition is a MenB drug substance. In some embodiments, the test immunogenic composition is a MenB fHBP A drug substance, a MenB fHBP B drug substance, or a MenB NadA drug substance. In some embodiments, the test immunogenic composition is a MenB fHBP A05 drug substance, a MenB fHBP B01 drug substance, or a MenB NadA1 drug substance. In some embodiments, the test immunogenic composition is a MenB fHBP A05tmN drug substance, a MenB fHBP B01smN drug substance, or a MenB truncated NadA1 drug substance. In some embodiments, the test immunogenic composition is a drug product. In some embodiments, the test immunogenic composition is a drug product comprising a MenB antigen or a MenB drug substance, comprising at least one, e.g. two or three, of a fHBP A drug substance or antigen, a fHBP B drug substance or antigen, and a NadA drug substance or antigen. In particular embodiments, the test immunogenic composition is a MenB or MenABCWY drug product comprising at least one, e.g. two or three, of a fHBP A drug substance, a fHBP B drug substance, and a NadA drug substance. In some embodiments, the test immunogenic composition is a MenB drug product, or MenB containing drug product such as MenABCWY drug product comprising at least one, e.g. two or three, of a fHBP A05 drug substance, a fHBP B01 drug substance, and a NadA1 drug substance. In some embodiments, the test immunogenic composition is a MenB drug product, or MenB containing drug product such as MenABCWY drug product, comprising at least one, e.g. two or three, of a fHBP A05tmN drug substance, a MenB fHBP B01smN drug substance, and a MenB truncated NadA1 drug substance. In some embodiments, the test immunogenic composition is a MenB fHBP A05tmN drug product, a MenB fHBP B01smN drug product, or a MenB truncated NadA1 drug product. In some embodiments, the test immunogenic composition is a MenABCWY drug product.PCT / US25 / 48115 26 September 2025 (26.09.2025)40

[0218] The present disclosure further relates to a method for manufacturing a vaccine which comprises at least one Neisseria meningitidis serogroup B (MenB) antigen, comprising:(a) preparing an immunogenic composition comprising at least one MenB antigen selected from the group consisting of a factor H binding protein (fHBP) A protein, a fHBP B protein, and Neisseria adhesin A (NadA) protein;(b) assaying the relative potency of said at least one MenB antigen in at least one test sample of the immunogenic composition by the above method for in vitro analysis; and(c) releasing the immunogenic composition for further manufacture step or for in vivo use if the results of step (b) indicate an acceptable relative potency.

[0219] By “assaying the relative potency”, it is meant a test of the functional integrity of the antigen to ensure that the antigen can elicit an immune response. The method according to the invention can provide quantitative information about the amounts of antigens having functional epitopes (e.g conformational epitopes) in an immunogenic composition. If this amount is compared to the amount in an immunogenic composition of known potency (also described herein as reference standard or Ref Std), then it is possible to calculate the relative potency of a test sample of an immunogenic composition. This relative potency is then converted to reportable units (AU / rnL).

[0220] In some embodiments, the standard immunogenic composition is a standard immunogenic composition that has known potency in an in vivo assay, e.g. it has a known serum bactericidal activity (SBA) titer. In some embodiments, the immunogenic composition is a test immunogenic composition that does not have a known potency in an in vivo assay. The assay may be used to analyze both a standard immunogenic composition and a test immunogenic composition, and the results of the analysis of the test immunogenic composition are compared to the results of the analysis of the standard immunogenic composition, and this comparison is used to express the test immunogenic composition’s potency relative to the known potency of the standard immunogenic composition.

[0221] By “acceptable relative potency”, it is meant a potency being within a range defined as suitable for release of the vaccine for further manufacture step or for in vivo use, for instance on the basis of the lowest potency resulting in clinically effective response. For example, an acceptable relative potency is less than 20%, less than 15%, less than 10%, less than 5%, less than 1%, less than 0.5% or less than 0.1 % variation of potency between a test vaccine and a standard vaccine of known potency.PCT / US25 / 48115 26 September 2025 (26.09.2025)41

[0222] In some embodiments, the at least one MenB antigen for which the relative potency is determined is selected from a fHBP A protein, a fHBP B protein, and a NadA protein. In some embodiments, the at least one MenB antigen for which the relative potency is determined is selected from fHBP A05, fHBP B01 , and NadA1. In some embodiments, the at least one MenB antigen for which the relative potency is determined is selected from fHBP A05tmN, fHBP B01smN, and truncated NadA1.

[0223] The method for manufacturing a vaccine which comprises at least one Neisseria meningitidis serogroup B (MenB) antigen according to the disclosure comprises a step of assaying the relative potency of said at least one MenB antigen via a method of in vitro analysis according to the disclosure. The methods of in vitro analysis according to the disclosure are used to analyze immunogenic composition comprising at least one MenB antigen. In some embodiments, the immunogenic composition is a drug product. In some embodiments, the immunogenic composition is a MenB drug product, or MenB containing drug product such as MenABCWY drug product comprising at least one, e.g. two or three, of a fHBP A drug substance, a fHBP B drug substance, and a NadA drug substance. In some embodiments, the immunogenic composition is a MenB drug product, or MenB containing drug product such as MenABCWY drug product comprising at least one, e.g. two or three, of a fHBP A05 or A05tmN drug substance, a fHBP B01 or B01smN drug substance, and a NadA1 or truncated NadA1 drug substance. In some embodiments, the assay is performed on a MenB or MenABCWY vaccine sample from a batch of final vaccine (drug product) to determine the fate of that batch e.g. whether the batch is suitable for release to the public, i.e. suitable for in vivo use. Usually, enough samples will be taken from batches to ensure compliance with statistical practices which are normal for vaccine release assays.

[0224] In some embodiments, the immunogenic composition is a MenB drug substance. In some embodiments, the immunogenic composition is a MenB fHBP A drug substance, a MenB fHBP B drug substance, or a MenB NadA drug substance. In some embodiments, the immunogenic composition is a MenB fHBP A05 drug substance, a MenB fHBP B01 drug substance, or a MenB NadA1 drug substance. In some embodiments, the test immunogenic composition is a MenB fHBP A05tmN drug substance, a MenB fHBP B01smN drug substance, or a MenB truncated NadA1 drug substance. In some embodiments, the assay is performed on a sample from a batch of a vaccine antigen (drug substance) to determine the fate of that batch e.g. whether the batch is suitable for further manufacture step (i.e. manufacture until incorporation into the drug product).

[0225] In some embodiments, the immunogenic composition sample is analyzed at full strength, i.e. in the form in which it is taken from the batch. In some embodiments, thePCT / US25 / 48115 26 September 2025 (26.09.2025)42 immunogenic composition sample is diluted. Dilutions will typically be achieved using buffer rather than with plain water. Such buffers can sometimes include surfactants such as polysorbate 20 or polysorbate 80.

[0226] In some embodiments, the method according to the disclosure is performed on at least one dilution of the immunogenic composition (i.e. immunogenic composition test sample or reference standard immunogenic composition sample). The dilution series will include at least 2 members, but usually will include more, e.g. 5, 10, or more members. The dilution series can be tested using the methods of the disclosure to provide a series of measurements that can be plotted against dilution. This series of measurements can be used to assess the vaccine’s relative potency.

[0227] In some embodiments, the immunogenic composition is a vaccine including at least one MenB antigen selected from a fHBP A protein, a fHBP B protein, and a NadA protein. In some embodiments, the vaccine includes at least one MenB antigen selected from fHBP A05, fHBP B01 , and NadA1. In some embodiments, the vaccine includes at least one MenB antigen selected from fHBP A05tmN, fHBP B01smN, and truncated NadA1. In some embodiments, the vaccine further comprises a meningococcal serogroup A, serogroup C, serogroup W, serogroup X and / or serogroup Y antigen.

[0228] In some embodiments, the analyzed MenB vaccine can elicit an immune response in human beings, which is protective against serogroup B meningococcus.EXAMPLES

[0229] The following examples are put forth so as to provide those of ordinary skill in the art with a complete disclosure and description of how to make and use the compositions and methods featured in the disclosure, and are not intended to limit the scope of what the Inventors regard as their disclosure. Efforts have been made to ensure accuracy with respect to numbers used (e.g., amounts, temperature, etc.) but some experimental errors and deviations should be accounted for.Example 1 : Characterization of anti-fHBP A05 mAbs and development of fHBP A05 Drug Substance (DS) Antigenicity ELISA Method.1. Characterization of anti-fHBP A05 mAbs

[0230] These results summarize the development of an ELISA method (sandwich format) using two anti-fHBP A05 monoclonal antibodies (mAbs) to quantify the antigenicity of A05tmN in fHBP non-adsorbed Drug Substance (DS).PCT / US25 / 48115 26 September 2025 (26.09.2025)43

[0231] The anti-fHBP A05 specific monoclonal antibodies (mAbs) were generated through hybridoma technology. Briefly, BALB / c mice were immunized with fHBP A05tmN protein (SEQ ID NO: 50) in combination with complete Freund's adjuvant (CFA) / alum. Following immunization, the fusion of splenocytes with NS-1 myeloma cells was performed and positive hybrids that produced the specific antibody of interest were selected. The final step included subcloning by limiting dilution to maintain clonality of hybridoma. An ELISA was performed on hybridoma supernatants to confirm the specificity of each mAb to A05 fHBP protein.

[0232] The epitope binning, binding affinity and stability indication of generated anti- fHBP A05 mAbs were assessed using Biolayer Interferometry (ForteBio) according to provider’s instructions. Anti-fHBP A05 JAR13 mAb (provided by Children’s Hospital Oakland Research Institute) was also included in the evaluation. To explore whether mAbs recognize conformational or linear epitopes, dot blot and epitope mapping using Hydrogen Deuterium Exchange Mass Spectrometry (HDX-MS) were performed.

[0233] The selected anti-fHBP A05 mAbs were further characterized for their bactericidal activity on MenB strains expressing the wild-type A05 antigen. The bactericidal activity of anti-fHBP A05 JAR13 mAb was also evaluated.

[0234] The SBA assay measures the ability of the antibodies to lyse and kill bacteria in the presence of complement. The source of complement was veal complement. Briefly, after a first step of culture on Mueller Hinton agar plate (Biomerieux) at 37°C with 5% CO2 overnight, bacteria (from a Neisseria meningitidis serogroup B strain expressing high level of the NadA1 , fHBP A05 or fHBP B01 protein, according to the tested mAb) were inoculated into BHI broth (BD) at an initial ODeoonm of 0.2 and incubated at 37°C and 100rpm. After 2.5h, bacteria were diluted in buffer (D-PBS+0.2% gelatin) and adjusted to 1.4x104CFU / mL. Two-fold dilutions of tested mAbs and rabbit IgG used as control (previously inactivated) were prepared in 96-well plates. Inactive veal complement (heat treated) was added into the wells of inactive blank and toxicity control. Active veal complement was added into the wells of test samples and active blank. The bacterial suspension adjusted to 1.4x104CFU / mL was added into each well and the reaction mixture was incubated at 37°C and 100 rpm for 1h. After this incubation period, the serum / complement / bacteria mixture was plated on Mueller Hinton agar plates (40pL / well) and incubated at 37°C with 5% CO2 for 12±4 hours according to the strain tested. Bacterial colonies were then counted after plate scan using Cybele software (Microvision). The SBA titer was defined as the minimal mAb concentration yielding more than 50% killing when compared to the mean CFU count of active blanks (bacteria + active complement) i.e. K50 value calculated for each plate. ForPCT / US25 / 48115 26 September 2025 (26.09.2025)44 each mAb or combination of mAbs, the CFU number counted after the SBA reaction was plotted in a graph according to the related concentration of mAb tested. To be considered as bactericidal, a mAb or combination of mAbs need to produce a decrease in CFU count below the K50 threshold (see for instance Figure 2).

[0235] Based on the data obtained, only 2 mAbs (anti-fHBP A05 1-2.1.6 (indicated as 1-2 on the figures) and 1-8.2.2 (indicated as 1-8 on the figures) mAbs) out of 8 constructed mAbs bind to conformational epitopes. Epitope binning further indicates that anti-fHBP A05 1-2.1.6, 1-8.2.2 and JAR13 antibodies target different bins (bin 2, bin 3 and bin4, respectively), which do not overlap (Figure 1 and Table 1). These two mAbs plus anti-fHBP A05 JAR13 mAb were tested individually or in combination with another mAb in serum bactericidal activity (SBA). The anti-fHBP A05 1-8.2.2 and JAR13 mAbs alone or in combination induced bactericidal activity in the presence of veal complement (Figure 2). The anti-fHBP A05 1-2.1.6 mAb also showed bactericidal activity in combination with either anti-fHBP A05 1-8.2.2 or JAR13 but it did not show any bactericidal activity alone in the presence of veal complement.

[0236] . The mAb binding signal at 300s of association (in nm) was analyzed byBiolayer Interferometry against native fHBP A05tmN antigen, or heat treated fHBP A05tmN for 7 days or for 14 days at 60°C. Anti-fHBP A05 mAbs 1-2.1.6, 1-8.2.2 and JAR13 were the most fHBP A05 antigen stability indicating (Figure 3).

[0237] A dot blot immunoassay using native (N) and denatured (D) fHBP A05tmN antigen indicates that only anti-fHBP A05 1-2.1.6, 1-8.2.2 and JAR13 mAbs could selectively detect the native A05 antigen (Figure 4), showing that these mAbs recognize a conformational epitope on the fHBP A05 antigen.

[0238] Epitope screening of A05tmN against anti-fHBP A05 1-2.1.6 mAb confirmed that the anti-fHBP A05 1-2.1.6 mAb recognizes a conformational epitope on the fHBP A05 antigen (Figure 5). The anti-fHBP A05 1-8.2.2 mAb was also confirmed to bind a conformational epitope on the fHBP A05 antigen by epitope screening (Figure 6).

[0239] The anti-fHBP A05 1-2.1.6 mAb, anti-fHBP A05 1-8.2.2 mAb, and anti-fHBP A05 JAR13 mAb were selected for the further assessment by a sandwich ELISA.

[0240] A summary of characterization of anti-fHBP A05 mAbs using various assays are shown in Table 1.PCT / US25 / 48115 26 September 2025 (26.09.2025)45Table 1. Summary of the Characterization of anti-fHBP A05 mAbs+ / -: mAbs are stability indicating at a lower extent ND: not done

[0241] Different coating (or capture) and detection mAb combinations were assayed in a sandwich ELISA format to determine the optimal mAb combinations for detecting fHBP A05 antigen in drug substance (DS) lots. The combination of anti-fHBP A05 1-2.1.6 mAb as a coating antibody, and the anti-fHBP A05 1-8.2.2 mAb conjugated to HRP as the detection mAb, was compared to the combination of anti-fHBP A05 JAR13 mAb, as the coating antibody, and either the anti-fHBP A05 1-2.1.6 mAb or the anti-fHBP A05 1-8.2.2 mAb conjugated to HRP as the detection antibody. The combination of anti-fHBP A05 1- 2.1.6 mAb as coating mAb and anti-fHBP A05 1-8.2.2-HRP as detection mAb gave higher OD values compared to the two other combinations. In conclusion, the anti-fHBP A05 1- 2.1.6 mAb and anti-fHBP A05 1 -8.2.2 mAb were selected from several mAbs, respectively, as a capture and a detection mAb, each capable to bind a different conformational epitope of fHBP A05.2. Specificity assessment of A05 antigenicity ELISA in A05 DS

[0242] The specificity of the fHBP A05 DS Antigenicity ELISA method was assessed using the other components of a MenB vaccine (fHBP B01smN, NadA1 and Detergent- Extracted Outer Membrane Vesicle (dOMV) DS) since the developed method can be used also for the measurement of A05 antigenicity in single-vial Drug Product. The specificity of the fHBP A05 DS Antigenicity ELISA method was further assessed using an E.coli lysate containing host cell proteins (lysate prepared from E.coli strain BL21 DE3) without MenB recombinant antigens. Additionally, the specificity of fHBP A05 DS Antigenicity ELISA method was assessed using DS formulation buffer.PCT / US25 / 48115 26 September 2025 (26.09.2025)46

[0243] As expected, none of the tested samples (fHBP B01smN, NadA1 , dOMV, E.coli lysate containing host cell proteins, or DS formulation buffer) generated a detectable signal in the assay. The antigenicity dose-response curve using an A05tmN DS as the reference standard (Ref Std) are shown in Figure 7 (A) and (B), the data using fHBP B01smN, NadA1 or dOMV DS are shown in Figure 7 (A), and the data using fHBP A05 DS Formulation buffer are shown in Figure 7 (B).

[0244] In conclusion, the developed fHBP A05 DS Antigenicity ELISA method is specific for the quantitation of fHBP A05 protein.Example 2: Characterization of anti-fHBP B01 mAbs and development of fHBP B01 DS Antigenicity ELISA Method.1. Characterization of anti-fHBP B01 mAbs

[0245] These results summarize the development of an ELISA method (sandwich format) using two anti-fHBP B01 mAbs to quantify the antigenicity of B01smN in fHBP nonadsorbed DS.

[0246] Ten anti-fHBP B01 specific mAbs were generated through hybridoma technology. Briefly, BALB / c mice were immunized with fHBP B01smN protein (SEQ ID NO: 52) in combination with CFA / alum. Following immunization, the fusion of splenocytes with NS-1 myeloma cells was performed and positive hybrids that produced the specific antibody of interest were selected. The final step included subcloning by limiting dilution to maintain clonality of hybridoma. An ELISA was performed on hybridoma supernatants to confirm the specificity of each mAb to B01 fHBP protein.

[0247] The epitope binning, binding affinity, and stability indication of fHBP B01 mAbs were assessed using Biolayer Interferometry according to provider’s instructions. Anti-fHBP B01 JAR5 mAb (provided by the Children’s Hospital Oakland Research Institute) was also evaluated as this mAb has been previously used for assessment of the fHBP B01 antigenicity. Characterization of mAbs binning indicates that 1-3.2.3 (indicated as 1-3 on the figures), and 2-13.1.5 (indicated as 2-13 on the figures) mAbs are non-competing (Figure 8). Epitope mapping of B01 mAbs using HDX-MS indeed indicates that 1-3.2.3, and 2-13.1.5 mAbs bind to various regions of B01 protein (Figure 9, Figure 10 and Table 3). Based on the obtained data, all fHBP B01 mAbs except fHBP B01 2-13.1.5. and JAR5 mAbs bind to linear epitopes.

[0248] The mAbs were tested individually or in combination with another mAb in SBA. All tested fHBP B01 mAbs alone (except JAR5) or in combination induced bactericidal activity in the presence of veal complement. Best bactericidal mAbs with veal complement were determined individually or in combo as being 1-3.2.3 and 2-13.1.5 mAbs (Table 2).PCT / US25 / 48115 26 September 2025 (26.09.2025)47Table 2. Bactericidal titers determination of individual mAbs or mAbs combinations using Veal Complement

[0249] The fHBP B01 1-3.2.3 mAb, fHBP B01 2-13.1.5 mAb, and fHBP B01 JAR5 mAb were selected for the further assessment by a sandwich ELISA.

[0250] A summary of characterization of anti-fHBP B01 mAbs using various assays are shown in Table 3.Table 3. Summary of the Characterization of anti-fHBP B01 mAbsND: No data

[0251] Different coating (or capture) and detection mAb combinations and concentrations were assayed in a sandwich ELISA format to determine the optimal assays conditions for detecting fHBP B01 antigen in the DS lots. The plates were coated with various concentrations of either anti-fHBP B01 1-3.2.3 mAb or anti-fHBP B01 2-13.1.5 mAb. The plates that were coated with the fHBP B01 1-3.2.3 mAb were detected with the fHBP B01 2-13.1.5 mAb conjugated to HRP or vice versa. The selected conditions were further compared with the fHBP B01 JAR5 mAb (as coating or detecting mAb). In conclusion, the anti-fHBP B01 1-3.2.3 mAb and the HRP-labelled anti-fHBP B01 2-13.1.5 mAb were selected, respectively, as a capture and a detection mAb for use in an ELISA assay.PCT / US25 / 48115 26 September 2025 (26.09.2025)482. Specificity assessment of B01 antigenicity ELISA in B01 DS

[0252] The specificity of the B01 DS Antigenicity ELISA method was assessed using the other components of a MenB vaccine (fHBP A05tmN, NadA1 and dOMV DS) since the developed method can be also used for the measurement of B01 antigenicity in single-vial Drug Product. The specificity of the fHBP B01 DS Antigenicity ELISA method was further assessed using an E.coli lysate containing host cell proteins (E.coli lysate without MenB antigens).

[0253] As expected, none of the tested samples (fHBP A05tmN, NadA1 , dOMV, E.coli lysate containing host cell proteins) generated a detectable signal in the assay. The antigenicity dose-response curve using B01smN DS as the Ref Std and the data using fHBP A05tmN, NadA1 , and dOMV is shown in Figure 11.

[0254] In conclusion, the developed fHBP B01 DS Antigenicity ELISA method is specific for the quantitation of fHBP B01 protein.Example 3: Characterization of anti-fHBP NadA1 mAbs and development of NadA1 DS Antigenicity ELISA Method.1. Characterization of anti-NadA1 mAbs

[0255] Ten NadA1 specific mAbs were generated through hybridoma technology. Briefly, BALB / c mice were immunized with a truncated NadA1 protein, i.e. without its membrane anchor domain and concomitant removal of the 23 amino acids signal peptide (SEQ ID NO: 54) in combination with either squalene / alum or complete Freund's adjuvant (CFA) / alum. Following immunization, the fusion of splenocytes with NS-1 myeloma cells was performed and positive hybrids that produced the specific antibody of interest were selected. The final step included subcloning by limiting dilution to maintain clonality of hybridoma. An ELISA was performed on hybridoma supernatants to confirm the specificity of each mAb to NadA1 protein. NadA1 sequence was derived from MenB MC58 strain.

[0256] The functionality / biological relevance of each mAb has been characterized using various assays including epitope mapping (HDX-MS), simple Wes, dot blotting, epitope binning, which are summarized in Table 4. Stability indication was characterized using methods well-known in the art. Simple Wes and Dot Blot showed that the NadA1 mAbs recognize conformational epitopes on the NadA1 protein. Epitope mapping and binning results are also shown on the Figure 12.

[0257] A study of binding efficiency of the generated anti-NadA1 mAbs was performed by ELISA. Both truncated NadA1 protein pre-adsorbed on aluminum phosphate (AIPO4) and truncated NadA1-dOMV DP (both pre-adsorbed on aluminum phosphate) werePCT / US25 / 48115 26 September 2025 (26.09.2025)49 directly coated on separate plates overnight. Each of NadA1 mAb was used as the primary detection antibody followed by incubation with the goat anti-mouse HRP. ELISA Score was evaluated based on optical density (OD) values for evaluation of the 10 mAbs NadA1 detection efficiency (Figure 13 and details in Table 4). Overall, all NadA1 mAbs had high affinity binding with NadA1 protein (Table 5).Table 4. Summary from characterization of NadA1 mAbs before the SBA testingTable 5. NadA1 mAbs affinity rankingHigher affinityLower affinity

[0258] The selected NadA1 mAbs were further characterized for their bactericidal activity. Serum bactericidal activity (SBA) of each NadA1 mAb plus 6 mAb combinations were tested against two MenB strains expressing the NadA1 protein (strain 1 and strain 2). None of the single tested NadA1 mAbs showed bactericidal activity in presence of vealPCT / US25 / 48115 26 September 2025 (26.09.2025)50 complement against strain 1. However, the NadA1 mAb 2-6.2.5 (also referred to as 2-6 mAb) showed bactericidal activity against strain 2 down to 1.9 pg / ml. Interestingly, all combos showed highly bactericidal activity against both MenB strains (Table 6).Table 6. SBA of individual or combinations of fHBP NadA1 specific mAbs against MenB Strains 1 and 2 expressing the NadA1 wild-type protein.*: Those mAb combos are able to induce bactericidal activity, but at the same time they induce cell toxicity when strain 1 was tested.

[0259] As per the results of NadA1 mAbs characterization, 2-21.3.4.2 (also named 2-21 herein) and 2-6.2.5 (also named 2-6 herein) were selected for NadA antigenicity assay based on the following main criteria: the mAbs are functional, recognize conformational epitopes, are stability-indicating and thus suitable for ELISA. NadA1 2-21.3.4.2 mAb is selected as capture mAb and NadA1 2-6.2.5 mAb is selected as detection mAb.2. Specificity assessment of NadA1 antigenicity ELISA in NadA1 DS

[0260] The specificity of the NadA1 DS Antigenicity ELISA method was assessed using the other components of a MenB vaccine (fHBP A05tmN, fHBP B01smN and dOMV DS) since the developed method can be also used for the measurement of NadA1 antigenicity in single-vial Drug Product. The specificity of the NadA1 DS Antigenicity ELISA method was further assessed using an E.coli lysate containing host cell proteins (E.coli lysate without MenB recombinant antigens). Additionally, the specificity of NadA1 DS Antigenicity ELISA method was assessed using a NadA1 DS formulation buffer.

[0261] Background level of signal was observed for fHBP A05 and B01 compared to the signal from NadA1 DS. A slight signal was observed when dOMV DS was used. This slightPCT / US25 / 48115 26 September 2025 (26.09.2025)51“non-specific” NadA signal may be contributed by the small amount of NadA naturally present in dOMV. However, there is minimal impact of the signal from dOMV.

[0262] In conclusion, the developed NadA1 DS Antigenicity ELISA is effectively specific for detecting the NadA1 DS antigenicity.Example 4: Antigenicity assay development for A05, B01, and NadA1 antigens in two MenB comprising DPs.1. Principle of the analytical procedure

[0263] The ELISA assays for A05, B01, and NadA1 antigens presented herein use the specific murine mAbs that have been described in examples 1 to 3 and were selected based on various criteria (e.g. stability indication, binning, binding affinity, conformational / linear epitopes, serum bactericidal activity). The developed methods allow assessing the antigenicity of MenB antigens for the manufacture of a vaccine comprising such MenB antigens. The antigenicity assays described herein have been performed on two Drug Products (DPs): MenB DP and MenPenta DP.

[0264] MenB DP is composed of the MenB A05tmN, B01smN, NadA1 , and dOMV antigens and AIPO4 adjuvant.MenPenta DP is composed of the MenB A05tmN, B01smN, NadA1 , and dOMV antigens and AIPO4 adjuvant and of the MenQuadfi® vaccine components, i.e. the Meningococcal serogroups A, C, Y and W polysaccharides, each independently conjugated to tetanus toxoid carrier protein.

[0265] The antigenicity assays for fHBP A05, fHBP B01, and NadA1 on MenB comprising DPs are sandwich ELISAs, using the coating mAbs and detection mAbs (conjugated to HRP) as listed in Table 7.Table 7. Monoclonal Antibodies used in development of A05tmN, B01smN, and NadA1 antigenicity ELISAs for a MenB comprising vaccine

[0266] Desorption of DP samples was evaluated. MenB DPsamples were treated with, or without, citrate (15% final volume) or phosphate (15% final volume) in order to determine if these commonly used AIPO4 adjuvant desorption methods could be applied to the DPPCT / US25 / 48115 26 September 2025 (26.09.2025)52 samples. As such, results shown that adsorption on adjuvant was not interfering (results not shown) and so moving forward, no desorption treatment was used for testing DP materials.2. Specificity assessment of A05 antigenicity ELISA in MenB comprising drug products

[0267] To confirm that the ELISA is specific for A05 in MenB DP matrix, a mock MenB DP vaccine was formulated at lab scale containing all components of MenB DP with the exception of A05tmN (MenB A05 dropout). The mock vaccine sample was tested with the A05 antigenicity ELISA, and results showed a lack of signal for this sample. In comparison, A05tmN was detected in whole MenB DP vaccine containing this antigen (MenB DP Ref Std) (Figure 14 A). Similar results were obtained with a mock MenPenta DP (MenPenta A05 dropout) compared to whole MenPenta DP vaccine (MenPenta DP Ref Std) (Figure 14 B).

[0268] These results confirm that the ELISA is specific for A05, and that other components in the complex MenB comprising DP matrices do not contribute to OD signals. These results align with the specificity assessment of the A05 antigenicity ELISA in A05tmN DS, where different individual MenB Drug substances (B01smN, NadA1 , or dOMV) were not detected by the assay (as shown above in example 1 part 2).3. Assessment of stability indicating ability of A05 antigenicity ELISA in MenB comprising drug products

[0269] T o confirm whether the A05 antigenicity ELISA was also stability indicating for drug products, a stability study was conducted (Figure 15).

[0270] Using a MenB DP Ref Std, and A05tmN DS as positive control for the assay, the A05 antigenicity was measured in MenB DP samples after storage at various heat stressed temperatures. After 12 months storage at 2-8°C, 25±2°C, the A05 antigenicity is still within 80% to 120% of the formulated amount, suggesting A05 antigen is stable in this Drug Product when stored at 2-8°C and 25±2°C for 12 months. A downward trend was observed in the samples stored at 37±2°C and more prominently in 45±2°C after 3 months. However, a more pronounced drop in A05 antigenicity was observed after 1 week of storage at 60±2°C, as evidenced by an antigenicity drop from 100 AU / mL to ~20 AU / mL (Figure 15A). After 2 months, the sample and / or specific A05 epitopes recognized by the mAb was too degraded, therefore a signal cannot be generated to pass parallelism.

[0271] Using a MenPenta DP Ref Std, and A05tmN DS as positive control for the assay, the A05 antigenicity was measured in MenPenta DP samples. After 6 months storage at 2-8°C, 25±2°C, the A05 antigenicity is still within 80% to 120% of the formulated amount, suggesting A05 antigen is stable in this drug product when stored at 2-8°C andPCT / US25 / 48115 26 September 2025 (26.09.2025)5325±2°C for 6 months. A downward trend was observed in the samples stored at 37±2°C and 45±2°C after 3 months. However, a more pronounced drop in A05 antigenicity was observed after 1 week of storage at 60±2°C, as evidenced by the inability to measure antigenicity as the sample and / or the specific A05 epitopes recognized by the mAb was too degraded to pass parallelism, since sufficient OD signal was not generated.

[0272] These results confirm that the anti-A05 monoclonal antibodies used in the assays are stability indicating in DPs matrices, and that an in vitro assay, like an ELISA, using these mAbs may be used for assessing the potency of A05 antigen either in A05 DS (see example 1) or in MenB comprising DPs (comprising A05 antigen). This assay can thus be used as a release test step of the vaccine manufacture process to determine whether a manufactured A05 drug substance can be incorporated in the drug product (i.e. final vaccine), and if a batch of a A05 comprising vaccine is suitable for release to the public.4. Specificity assessment of B01 antigenicity ELISA

[0273] T o confirm that the ELISA is specific for B01 , a mock MenB DP vaccine was formulated at lab scale containing all components of MenB DP with the exception of B01smN (MenB B01 dropout). The mock vaccine sample was tested with the B01 antigenicity ELISA, and results showed a lack of signal for this sample. In comparison, B01smN was detected in whole MenB DP vaccine containing this antigen (MenB DP Ref Std) (Figure 16 A). Similar results were obtained with a mock MenPenta DP (MenPenta B01 dropout) compared to whole MenPenta DP vaccine (MenPenta DP Ref Std) (Figure 16 B).

[0274] Results confirm that the ELISA is specific for B01 , and that other components in the complex MenB DPs matrices do not contribute to OD signals. These results align with the specificity assessment of the B01 antigenicity ELISA in B01smN DS, where different individual MenB Drug substances (A05tmN, NadA1 , or dOMV) were not detected by the assay (as shown above in example 2 part 2).5. Assessment of stability indicating ability of B01 antigenicity ELISA in MenB comprising drug products

[0275] To confirm whether the B01 antigenicity ELISA was also stability indicating for drug products, a stability study was conducted (Figure 17).

[0276] Using a MenB DP Ref Std, and B01smN DS as positive control for the assay, the B01 antigenicity was measured in MenB DP samples after storage at various heat stressed temperatures. After 12 months storage at 2-8°C, 25±2°C, the B01 antigenicity is still within 80% to 120% of the formulated amount, suggesting B01 antigen is stable in thisPCT / US25 / 48115 26 September 2025 (26.09.2025)54Drug Product when stored at 2-8°C and 25±2°C for 12 months. A downward trend was observed in the samples stored at 37±2°C and 45±2°C after 3 months. However, a more pronounced drop in B01 antigenicity was observed after 2 weeks of storage at 60±2°C, as evidenced by an antigenicity drop from 100 AU / rnL to ~60 AU / rnL. After 1 month, the sample and / or specific B01 epitopes recognized by the mAb was too degraded, therefore a signal cannot be generated to pass parallelism (Figure 17 A).

[0277] Using a MenPenta DP Ref Std, and B01smN DS as positive control for the assay, the B01 antigenicity was measured in MenPenta DP samples. After 6 months storage at 2-8°C, 25±2°C, the B01 antigenicity is still within 80% to 120% of the formulated amount, suggesting B01 antigen is stable in this Drug Product when stored at 2-8°C and 25±2°C for 6 months. A downward trend was observed in the samples stored at 37±2°C and 45±2°C after 3 months. However, a more pronounced drop in B01 antigenicity was observed after 1 week of storage at 60±2°C, as evidenced by an antigenicity drop from 100 AU / mL to ~30 AU / mL. After 2 weeks, the sample and / or specific B01 epitopes recognized by the mAb was too degraded, therefore a signal cannot be generated to pass parallelism (Figure 17 B).

[0278] These results confirm that the anti-B01 monoclonal antibodies used in the assay are stability indicating in DPs matrices, and that an in vitro assay, like an ELISA, using these mAbs may be used for assessing the potency of B01 antigen either in B01 DS (see example 2) or in MenB comprising DPs (comprising B01 antigen). This assay can thus be used as a release test step of the vaccine manufacture process to determine whether a manufactured B01 drug substance can be incorporated in the drug product (i.e. final vaccine), and if a batch of a B01 comprising vaccine is suitable for release to the public.6. Specificity assessment of NadA1 antigenicity ELISA

[0279] To confirm that the ELISA is specific for NadA1 , a mock MenB DP vaccine (at 2 different doses, HD and LD) was formulated at lab scale containing all components of MenB DP with the exception of the truncated NadA1 (MenB NadA dropout). The mock vaccine samples without NadA1 were tested with the NadA1 antigenicity ELISA. Both mock samples showed no notable signal compared to the reference standard, which detected the truncated NadA1 present in the MenB DP vaccine (Figure 18 A). Similar results were obtained with mock MenPenta DP vaccines (MenPenta NadA dropout) compared to whole MenPenta DP vaccine (MenPenta DP Ref Std) (Figure 18 B).

[0280] Results confirm that the ELISA is specific for NadA1 , and that other components in the complex MenB DPs matrices do not contribute to OD signals. These results align with the specificity assessment of the NadA1 antigenicity ELISA in truncatedPCT / US25 / 48115 26 September 2025 (26.09.2025)55NadA1 DS, where different individual MenB Drug substances (A05tmN, BOIsmN, or dOMV) were not detected by the assay (see Example 3 Part 2).7. Assessment of stability indicating ability of NadA1 antigenicity ELISA in MenB comprising drug products

[0281] To confirm whether the NadA1 antigenicity ELISA was also stability indicating, a stability study was conducted by bioprocess stability group (Figure 19).

[0282] Using a MenB DP Ref Std, and truncated NadA1 DS as positive control for the assay, the NadA1 antigenicity was measured in MenB DP samples stored in glass vials. After 12 months storage at 2-8°C, and 6 months storage at 25±2°C, the NadA1 antigenicity was still approximately 80% to 120% of the formulated amount, suggesting NadA1 antigen is stable when stored at 2-8°C and 25±2°C for 12 months and 6 months, respectively. A downward trend was observed in the samples stored at 37±2°C after 1 month. A more pronounced drop in NadA1 antigenicity was observed after 3 days of storage at 45±2°C, as evidenced by an antigenicity drop by approximately 40 AU / mL. Further storage at 45±2°C caused the sample and / or specific mAb NadA1 epitopes to be too degraded to pass parallelism. Similar degradation occurred in samples after 3 days of storage at 60±2°C.

[0283] Using a MenPenta DP Ref Std, and truncated NadA1 DS as positive control for the assay, the NadA1 antigenicity was measured in MenB DP samples stored in glass vials. After 6 months storage at 2-8°C and 25±2°C, the NadA1 antigenicity is still approximately 80% to 120% of the formulated amount, suggesting NadA1 antigen is stable when stored at 2-8°C and 25±2°C for 6 months. A downward trend was observed in the samples stored at 37±2°C after 1 month. A more pronounced drop in NadA1 antigenicity was observed after 1 week of storage at 45±2°C, as evidenced by an antigenicity drop from 100 AU / mL to approximately 2 AU / mL. Further storage at 45±2°C caused the sample and / or specific mAb NadA1 epitopes to be too degraded to pass parallelism. Similar degradation occurred in samples after 1 week of storage at 60±2°C.

[0284] This result confirms that the anti-NadA1 monoclonal antibodies used in the assay are stability indicating in DPs matrices, and that an in vitro assay, like an ELISA, using these mAbs may be used for assessing the potency of NadA1 antigen either in NadA1 DS (see example 3) or in MenB comprising DPs (comprising NadA1 antigen). This assay can thus be used as a release test step of the vaccine manufacture process to determine whether a manufactured NadA1 drug substance can be incorporated in the drug product (i.e. final vaccine), and if a batch of a NadA1 comprising vaccine is suitable for release to the public.

Claims

CLAIMS1. A monoclonal antibody targeting a Neisseria meningitidis serogroup B (MenB) antigen, comprising a heavy chain variable (VH) domain comprising a H-CDR1 of sequence SEQ ID NO: 1 , a H-CDR2 of sequence SEQ ID NO: 2, and a H-CDR3 of sequence SEQ ID NO: 3; and a light chain variable (VL) domain comprising a L-CDR1 of SEQ ID NO: 4, a L-CDR2 of SEQ ID NO: 5 and a L-CDR3 of SEQ ID NO: 6, wherein the MenB antigen is fHBP A protein.

2. The monoclonal antibody of claim 1 , which comprises a VH domain that has at least 70% sequence identity with SEQ ID NO: 37 and / or a VL domain that has at least 70% sequence identity with SEQ ID NO: 38.

3. The monoclonal antibody of claim 1 or 2, which binds to a conformational epitope of said MenB fHBP A protein.

4. A monoclonal antibody targeting a Neisseria meningitidis serogroup B (MenB) antigen, comprising a heavy chain variable (VH) domain comprising a H-CDR1 of sequence SEQ ID NO: 7, a H-CDR2 of sequence SEQ ID NO: 8, and a H-CDR3 of sequence SEQ ID NO: 9; and a light chain variable (VL) domain comprising a L-CDR1 of SEQ ID NO: 10, a L-CDR2 of SEQ ID NO: 11 and a L-CDR3 of SEQ ID NO: 12, wherein the MenB antigen is fHBP A protein.

5. The monoclonal antibody of claim 4, which comprises a VH domain that has at least 70% sequence identity with SEQ ID NO: 39 and / or a VL domain that has at least 70% sequence identity with SEQ ID NO: 40.

6. The monoclonal antibody of claim 4 or 5, which binds to a conformational epitope of said MenB fHBP A protein.

7. A monoclonal antibody targeting a Neisseria meningitidis serogroup B (MenB) antigen, comprising a heavy chain variable (VH) domain comprising a H-CDR1 of sequence SEQ ID NO: 13, a H-CDR2 of sequence SEQ ID NO: 14, and a H-CDR3 of sequence SEQ ID NO: 15; and a light chain variable (VL) domain comprising a L- CDR1 of SEQ ID NO: 16, a L-CDR2 of SEQ ID NO: 17 and a L-CDR3 of SEQ ID NO: 18, wherein the MenB antigen is fHBP B protein.

8. The monoclonal antibody of claim 7, which comprises a VH domain that has at least 70% sequence identity with SEQ ID NO: 41 and / or a VL domain that has at least 70% sequence identity with SEQ ID NO: 42.

9. A monoclonal antibody targeting a Neisseria meningitidis serogroup B (MenB) antigen, comprising a heavy chain variable (VH) domain comprising a H-CDR1 of sequence SEQ ID NO: 19, a H-CDR2 of sequence SEQ ID NO: 20, and a H-CDR3 of sequence SEQ ID NO: 21 ; and a light chain variable (VL) domain comprising a L- CDR1 of SEQ ID NO: 22, a L-CDR2 of SEQ ID NO: 23 and a L-CDR3 of SEQ ID NO: 24, wherein the MenB antigen is fHBP B protein.

10. The monoclonal antibody of claim 9, which comprises a VH domain that has at least 70% sequence identity with SEQ ID NO: 43 and / or a VL domain that has at least 70% sequence identity with SEQ ID NO: 44.

11. The monoclonal antibody of claim 9 or 10, which binds to a conformational epitope of said MenB fHBP B protein.

12. A monoclonal antibody targeting a Neisseria meningitidis serogroup B (MenB) antigen, comprising a heavy chain variable (VH) domain comprising a H-CDR1 of sequence SEQ ID NO: 25, a H-CDR2 of sequence SEQ ID NO: 26, and a H-CDR3 of sequence SEQ ID NO: 27; and a light chain variable (VL) domain comprising a L- CDR1 of SEQ ID NO: 28, a L-CDR2 of SEQ ID NO: 29 and a L-CDR3 of SEQ ID NO: 30, wherein the MenB antigen is NadA protein.

13. The monoclonal antibody of claim 12, which comprises a VH domain that has at least 70% sequence identity with SEQ ID NO: 45 and / or a VL domain that has at least 70% sequence identity with SEQ ID NO: 46.

14. The monoclonal antibody of claim 12 or 13, which binds to a conformational epitope of said MenB NadA protein.

15. A monoclonal antibody targeting a Neisseria meningitidis serogroup B (MenB) antigen, comprising a heavy chain variable (VH) domain comprising a H-CDR1 of sequence SEQ ID NO: 31 , a H-CDR2 of sequence SEQ ID NO: 32, and a H-CDR3 of sequence SEQ ID NO: 33; and a light chain variable (VL) domain comprising a L-CDR1 of SEQ ID NO: 34, a L-CDR2 of SEQ ID NO: 35 and a L-CDR3 of SEQ ID NO: 36, wherein the MenB antigen is NadA protein.

16. The monoclonal antibody of claim 15, which comprises a VH domain that has at least 70% sequence identity with SEQ ID NO: 47 and / or a VL domain that has at least 70% sequence identity with SEQ ID NO: 48.

17. The monoclonal antibody of claim 15 or 16, which binds to a conformational epitope of said MenB NadA protein.

18. A pair of monoclonal antibodies targeting a Neisseria meningitidis serogroup B (MenB) antigen, comprising:(a) a first monoclonal antibody against factor H binding protein (fHBP) A protein that comprises a heavy chain variable (VH) domain comprising a H-CDR1 of sequence SEQ ID NO: 1 , a H-CDR2 of sequence SEQ ID NO: 2, and a H-CDR3 of sequence SEQ ID NO: 3; and a light chain variable (VL) domain comprising a L-CDR1 of SEQ ID NO: 4, a L-CDR2 of SEQ ID NO: 5 and a L-CDR3 of SEQ ID NO: 6; and(b) a second monoclonal antibody against fHBP A protein that comprises a VH domain comprising a H-CDR1 of sequence SEQ ID NO: 7, a H-CDR2 of sequence SEQ ID NO: 8, and a H-CDR3 of sequence SEQ ID NO: 9; and a VL domain comprising a L-CDR1 of sequence SEQ ID NO: 10, a L-CDR2 of sequence SEQ ID NO: 11 and a L-CDR3 of sequence SEQ ID NO: 12.

19. The pair of monoclonal antibodies of claim 18, wherein said first monoclonal antibody against fHBP A protein comprises a VH domain that has at least 70% sequence identity with SEQ ID NO: 37, and / or a VL domain that has at least 70% sequence identity with SEQ ID NO: 38; and / or wherein said second monoclonal antibody against a fHBP A protein comprises a VH domain that has at least 70% sequence identity with SEQ ID NO: 39, and / or a VL domain that has at least 70% sequence identity with SEQ ID NO: 40.

20. A pair of monoclonal antibodies targeting a Neisseria meningitidis serogroup B (MenB) antigen, comprising:(a) a first monoclonal antibody against factor H binding protein (fHBP) B protein that comprises a heavy chain variable (VH) domain comprising a H-CDR1 ofsequence SEQ ID NO: 13, a H-CDR2 of sequence SEQ ID NO: 14, and a H- CDR3 of sequence SEQ ID NO: 15; and a light chain variable (VL) domain comprising a L-CDR1 of sequence SEQ ID NO: 16, a L-CDR2 of sequence SEQ ID NO: 17 and a L-CDR3 of sequence SEQ ID NO: 18; and(b) a second monoclonal antibody against fHBP B protein that comprises a VH domain comprising a H-CDR1 of sequence SEQ ID NO: 19, a H-CDR2 of sequence SEQ ID NO: 20, and a H-CDR3 of sequence SEQ ID NO: 21 ; and a VL domain comprising a L-CDR1 of sequence SEQ ID NO: 22, a L-CDR2 of sequence SEQ ID NO: 23 and a L-CDR3 of sequence SEQ ID NO: 24.21 . The pair of monoclonal antibodies of claim 20, wherein said first monoclonal antibody against fHBP B protein comprises a VH domain that has at least 70% sequence identity with SEQ ID NO: 41 , and / or a VL domain that has at least 70% sequence identity with SEQ ID NO: 42; and / or wherein said second monoclonal antibody against fHBP B protein comprises a VH domain that has at least 70% sequence identity with SEQ ID NO: 43, and / or a VL domain that has at least 70% sequence identity with SEQ ID NO: 44.

22. A pair of monoclonal antibodies targeting a Neisseria meningitidis serogroup B (MenB) antigen, comprising:(a) a first antibody against Neisseria adhesin A (NadA) protein that comprises a heavy chain variable (VH) domain comprising a H-CDR1 of sequence SEQ ID NO: 25, a H-CDR2 of sequence SEQ ID NO: 26, and a H-CDR3 of sequence SEQ ID NO: 27; and a light chain variable (VL) domain comprising a L-CDR1 of sequence SEQ ID NO: 28, a L-CDR2 of sequence SEQ ID NO: 29 and a L-CDR3 of sequence SEQ ID NO: 30; and(b) a second antibody against NadA protein that comprises a VH domain comprising a H-CDR1 of sequence SEQ ID NO: 31 , a H-CDR2 of sequence SEQ ID NO: 32, and a H-CDR3 of sequence SEQ ID NO: 33; and a VL domain comprising a L- CDR1 of sequence SEQ ID NO: 34, a L-CDR2 of sequence SEQ ID NO: 35 and a L-CDR3 of sequence SEQ ID NO: 36.

23. The pair of monoclonal antibodies of claim 22, wherein said first monoclonal antibody against NadA protein comprises a VH domain that has at least 70% sequence identity with SEQ ID NO: 45, and / or a VL domain that has at least 70% sequence identity with SEQ ID NO: 46; and / orwherein said second monoclonal antibody against NadA protein comprises a VH domain that has at least 70% sequence identity with SEQ ID NO: 47, and / or a VL domain that has at least 70% sequence identity with SEQ ID NO: 48.

24. The pair of monoclonal antibodies of any one of claims 18 to 23, wherein at least one of the monoclonal antibodies of said pair recognizes a conformational epitope of said MenB antigen.

25. The pair of monoclonal antibodies of any one of claims 18 to 24, wherein the second antibody of said pair recognizes a conformational epitope of said MenB antigen.

26. The pair of monoclonal antibodies of any one of claims 18 to 19 or 22 to 23, wherein the first antibody of said pair recognizes a first conformational epitope of said MenB antigen, and the second antibody of said pair recognizes a second conformational epitope of said MenB antigen.

27. The pair of monoclonal antibodies of any one of claims 18 to 26, wherein at least one of the monoclonal antibodies of said pair is bactericidal.

28. The pair of monoclonal antibodies of any one of claims 18 to 27, wherein second antibody of said pair is bactericidal.

29. The pair of monoclonal antibodies of any one of claims 20 to 23, wherein the first antibody and the second antibody of said pair are bactericidal.

30. Use of a pair of monoclonal antibodies according to any one of claims 18 to 29, to detect a MenB antigen in a test sample.

31. The use of claim 30, wherein the MenB antigen is detected by enzyme-linked immunosorbent assay (ELISA), wherein said first monoclonal antibody is a capture antibody; and wherein said second monoclonal antibody is a detection antibody.

32. A method for detecting a Neisseria meningitidis serogroup B (MenB) antigen in a test sample comprising:(a) contacting the test sample with a first monoclonal antibody of a pair of monoclonal antibodies according to any one of claims 18 to 29, wherein said first monoclonal antibody is a capture antibody and is immobilized to a solid support;(b) contacting complexes formed by the capture antibody and MenB antigen present in the test sample with a second monoclonal antibody of said pair of monoclonal antibodies according to any one of claims 18 to 29, wherein said second monoclonal antibody is a detection antibody;(c) detecting the presence, or absence, of MenB antigen bound to the capture antibody using a detection means for the detection antibody.

33. A method for quantifying a Neisseria meningitidis serogroup B (MenB) antigen in a test sample comprising:(a) contacting the test sample with a first monoclonal antibody of a pair of monoclonal antibodies according to any one of claims 18 to 29, wherein said first monoclonal antibody is a capture antibody and is immobilized to a solid support;(b) contacting complexes formed by the capture antibody and MenB antigen present in the test sample with a second monoclonal antibody of said pair of monoclonal antibodies according to any one of claims 18 to 29, wherein said second monoclonal antibody is a detection antibody;(c) measuring the quantity of MenB antigen bound to the capture antibody using a detection means for the detection antibody.

34. The method of claim 32 or 33, wherein at least one of the monoclonal antibodies of said pair recognizes a conformational epitope of said MenB antigen.

35. The method of any one of claims 32 to 34, wherein the detection antibody of said pair recognizes a conformational epitope of said MenB antigen.

36. The method of any one of claims 32 to 35, wherein the detection antibody of said pair recognizes a first conformational epitope of said MenB antigen, and the capture antibody of said pair recognizes a second conformational epitope of said MenB antigen.

37. The method of any one of claims 32 to 36, wherein at least one of the monoclonal antibodies of said pair is bactericidal.

38. The method of any one of claims 32 to 37, wherein the detection antibody of said pair is bactericidal.

39. The method of any one of claims 32 to 38, wherein the capture antibody and the detection antibody of said pair are bactericidal.

40. The method of any one of claims 32 to 39, wherein said MenB antigen is adsorbed on aluminum adjuvant.41 . The method of any one of claims 32 to 40, wherein said test sample is a vaccine sample.

42. The method of any one of claims 32 to 41 , wherein the presence or quantity of MenB antigen is determined by sandwich ELISA.

43. The method of any one of claims 32 to 42, wherein said capture antibody and said detection antibody bind to different epitopes on said MenB antigen.

44. The method of any one of claims 32 to 43, wherein the MenB antigen is selected from the group consisting of a factor H binding protein (fHBP) A protein, a fHBP B protein, and a Neisseria adhesin A (NadA) protein.

45. The method according to any one of claims 32 to 44, wherein said test sample is a MenB fHBP A drug substance, a MenB fHBP B drug substance, a MenB NadA drug substance, or a MenB drug product comprising at least one of a fHBP A drug substance, a fHBP B drug substance, and a NadA drug substance.

46. The method according to any one of claims 32 to 45, wherein said test sample further comprises a meningococcal serogroup A, serogroup C, serogroup W, serogroup Y, and / or serogroup X antigen.

47. A method for in vitro analysis of a test sample of an immunogenic composition which comprises at least one Neisseria meningitidis serogroup B (MenB) antigen, comprising:(a) performing the method of any one of claims 33 to 46 on the test sample and, optionally, on at least one dilution of the test sample;(b) performing the method of any one of claims 33 to 46 on a standard immunogenic composition sample of known potency and, optionally, on at least one dilution of the standard sample; and(c) comparing the results from steps (a) and (b) to determine the relative potency of at least one MenB antigen in the test immunogenic composition compared to the potency of said at least one MenB antigen in the standard immunogenic composition.

48. A method for in vitro analysis of a test sample of an immunogenic composition which comprises at least one Neisseria meningitidis serogroup B (MenB) antigen, comprising:(a) performing the method of any one of claims 33 to 46 on the test sample and, optionally, on at least one dilution of the test sample;(b) performing the method of any one of claims 33 to 46 on a standard immunogenic composition sample of known concentration of said MenB antigen and, optionally, on at least one dilution of the standard sample; and(c) comparing the results from steps (a) and (b) to determine the relative potency of the at least one MenB antigen in the test immunogenic composition compared to the potency of said at least one MenB antigen in the standard immunogenic composition.

49. The method according to claim 47 or 48, wherein said immunogenic composition is a MenB fHBP A drug substance, a MenB fHBP B drug substance, a MenB NadA drug substance, or a MenB drug product comprising at least one of a fHBP A drug substance, a fHBP B drug substance, and a NadA drug substance.

50. The method according to any one of claims 47 to 49, wherein said immunogenic composition further comprises a meningococcal serogroup A, serogroup C, serogroup W, serogroup Y, and / or serogroup X antigen.51 . A method for manufacturing a vaccine which comprises at least one Neisseria meningitidis serogroup B (MenB) antigen, comprising:(a) Preparing an immunogenic composition comprising at least one MenB antigen selected from the group consisting of a factor H binding protein (fHBP) A protein, a fHBP B protein, and Neisseria adhesin A (NadA) protein;(b) assaying the relative potency of said at least one MenB antigen in at least one test sample of the immunogenic composition by the method of any one of claims 47 to 50; and(c) releasing the immunogenic composition for further manufacture step or for in vivo use if the results of step (b) indicate an acceptable relative potency.

52. The method according to any one of claims 47 to 51 , wherein the at least one MenB antigen for which the relative potency is determined is selected from a factor H binding protein (fHBP) A protein, a fHBP B protein, and a Neisseria adhesin A (NadA).

53. The method according to any one of claims 47 to 52, wherein said immunogenic composition is a MenB fHBP A drug substance, a MenB fHBP B drug substance, a MenB NadA drug substance, or a MenB drug product comprising at least one of a fHBP A drug substance, a fHBP B drug substance, and a NadA drug substance.

54. The method according to any one of claims 47 to 53, wherein said immunogenic composition further comprises a meningococcal serogroup A, serogroup C, serogroup W, serogroup Y, and / or serogroup X antigen.

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