Imprinting of IgA responses in previously infected individuals receiving bivalent mRNA vaccines (WT and BA.4/BA.5 or WT and BA.1)

• Published in: International journal of infectious diseases Vol. 146; p. 107147
• Main Authors: Goh, Yun Shan, Fong, Siew‐Wai, Hor, Pei Xiang, Loh, Chiew Yee, Tay, Matthew Zirui, Wang, Bei, Salleh, Siti Nazihah Mohd, Ngoh, Eve Zi Xian, Lee, Raphael Tze Chuen, Poh, Xuan Ying, Lee, I. Russel, Rao, Suma, Chia, Po Ying, Maurer-Stroh, Sebastian, Wang, Cheng-I, Leo, Yee‐Sin, Lye, David C., Young, Barnaby Edward, Ng, Lisa F.P., Renia, Laurent
• Format: Journal Article
• Language: English
• Published: Canada Elsevier Ltd 01.09.2024; Elsevier
• Subjects: Adult; Aged; Antibodies, Viral - blood; Bivalent; COVID-19 - immunology; COVID-19 - prevention & control; COVID-19 - virology; COVID-19 Vaccines - administration & dosage; COVID-19 Vaccines - immunology; EG.5.1; Female; Humans; IgA; Immunization, Secondary; Immunoglobulin A - blood; Male; Middle Aged; mRNA vaccine; mRNA Vaccines; SARS-CoV-2; SARS-CoV-2 - genetics; SARS-CoV-2 - immunology; Spike Glycoprotein, Coronavirus - genetics; Spike Glycoprotein, Coronavirus - immunology; Vaccination; Vaccines, Synthetic - administration & dosage; Vaccines, Synthetic - immunology; Variant; Young Adult; Bivalent; Variant; EG.5.1; SARS-CoV-2; IgA; mRNA vaccine
• ISSN: 1201-9712; 1878-3511; 1878-3511
• DOI: 10.1016/j.ijid.2024.107147

•Immune escape of SARS-CoV-2 variants spurred the development of bivalent vaccines.•We compared antibody response following monovalent or bivalent mRNA vaccination.•While IgG responses are similar, IgA responses are lower post bivalent booster.•IgA are particularly lower in bivalent-booster-vaccinees with prior infection.•IgA are skewed towards WT in bivalent-booster-vaccinees with prior infection. The emergence of new SARS-CoV-2 variants has led to the development of Omicron-targeting bivalent mRNA vaccines. It is crucial to understand how bivalent vaccines may improve antibody responses against new variants. A total of 107 participants, who had three COVID-19 WT mRNA vaccine doses, were recruited, and given either a monovalent (WT) or a bivalent mRNA vaccination (Pfizer/BioNTech Bivalent (WT and BA.4/BA.5) or Moderna Bivalent (WT and BA.1). Blood samples were taken before booster and at 28 days post-booster. We found significantly lower fold change in serum binding IgA responses against BA.1, BA.5 and EG.5.1 spike in the bivalent booster group, compared with the monovalent (WT) booster group, following vaccination. However, this was only observed in individuals with prior infection. The relative fold change in serum binding IgA response was more skewed towards WT over variant (BA.1, BA.5 or EG.5.1) spike in previously infected bivalent-booster-vaccinees, as compared with previously infected monovalent-(WT)-booster-vaccinees. The findings suggest imprinting of antibody responses that is shaped by the first vaccination (WT spike). Previous infection also affects the boosting effect of follow-up vaccination. Studies are needed to understand how to induce a robust and long-lasting IgA immunity for protection against COVID-19 infection.