Analysis of B-cell receptor repertoire to evaluate the immunogenicity of SARS-CoV-2 RBD mRNA vaccine: MAFB-7256a (DS-5670d)

• Published in: Frontiers in immunology Vol. 15; p. 1468760
• Main Authors: Ohji, Goh, Funakoshi, Yohei, Yakushijin, Kimikazu, Matsutani, Takaji, Sasaki, Tomoki, Kusakabe, Takahiro, Matsumoto, Sakuya, Koyama, Taiji, Nagatani, Yoshiaki, Kurata, Keiji, Kimbara, Shiro, Kiyota, Naomi, Minami, Hironobu
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Media S.A 07-10-2024
• Subjects: Adult; Antibodies, Neutralizing - blood; Antibodies, Neutralizing - immunology; Antibodies, Viral - blood; Antibodies, Viral - immunology; B-cell receptor repertoire; coronavirus antibody database; COVID-19 - immunology; COVID-19 - prevention & control; COVID-19 Vaccines - immunology; Female; Humans; Immunogenicity, Vaccine; Immunology; Male; mRNA RBD vaccine; mRNA Vaccines - immunology; quantification of antigen-specific antibody sequence; Receptors, Antigen, B-Cell - genetics; Receptors, Antigen, B-Cell - immunology; SARS-CoV-2; SARS-CoV-2 - immunology; Spike Glycoprotein, Coronavirus - genetics; Spike Glycoprotein, Coronavirus - immunology; Vaccination; Vaccines, Synthetic - immunology; SARS-CoV-2; mRNA RBD vaccine; quantification of antigen-specific antibody sequence; B-cell receptor repertoire; coronavirus antibody database
• ISSN: 1664-3224; 1664-3224
• DOI: 10.3389/fimmu.2024.1468760

A monovalent Omicron XBB.1.5 mRNA RBD analogue vaccine, MAFB-7256a (DS-5670d), was newly developed and approved in Japan in the Spring of 2024 for the prevention of COVID-19. However, clinical efficacy data for this vaccine are currently lacking. We previously established the Quantification of Antigen-specific Antibody Sequence (QASAS) method to assess the response to SARS-CoV-2 vaccination at the mRNA level using B-cell receptor (BCR) repertoire assays and the Coronavirus Antibody Database (CoV-AbDab). Here, we used this method to evaluate the immunogenicity of MAFB-7256a. We analyzed repeated blood samples using the QASAS method from three healthy volunteers before and after MAFB-7256a vaccination. BCR response increased rapidly one week post-vaccination and then decreased, as with conventional vaccine. Notably, the matched sequences after MAFB-7256a vaccination specifically bound to the receptor-binding domain (RBD), with no sequences binding to other epitopes. These results validate that MAFB-7256a is an effective vaccine that exclusively induces antibodies specific for the RBD, demonstrating its targeted immunogenic effect.