AUTHOR=Girard Bethany , Baum-Jones Elisabeth , Best Rebecca L. , Campbell Thomas W. , Coupart Jack , Dangerfield Kyla , Dhal Abhilash , Jhatro Michael , Martinez Brian , Reifert Jack , Shon John , Zhang Minlu , Waitz Rebecca , Chalkias Spyros , Edwards Darin K. , Maglinao Maha , Paris Robert , Pajon Rolando 

TITLE=Profiling antibody epitopes induced by mRNA-1273 vaccination and boosters

JOURNAL=Frontiers in Immunology

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2024.1285278

DOI=10.3389/fimmu.2024.1285278

ISSN=1664-3224

ABSTRACT=<sec><title>Background</title><p>Characterizing the antibody epitope profiles of messenger RNA (mRNA)-based vaccines against SARS-CoV-2 can aid in elucidating the mechanisms underlying the antibody-mediated immune responses elicited by these vaccines.</p></sec><sec><title>Methods</title><p>This study investigated the distinct antibody epitopes toward the SARS-CoV-2 spike (S) protein targeted after a two-dose primary series of mRNA-1273 followed by a booster dose of mRNA-1273 or a variant-updated vaccine among serum samples from clinical trial adult participants.</p></sec><sec><title>Results</title><p>Multiple S-specific epitopes were targeted after primary vaccination; while signal decreased over time, a booster dose after &gt;6 months largely revived waning antibody signals. Epitope identity also changed after booster vaccination in some subjects, with four new S-specific epitopes detected with stronger signals after boosting than with primary vaccination. Notably, the strength of antibody responses after booster vaccination differed by the exact vaccine formulation, with variant-updated mRNA-1273.211 and mRNA-1273.617.2 booster formulations inducing significantly stronger S-specific signals than a mRNA-1273 booster.</p></sec><sec><title>Conclusion</title><p>Overall, these results identify key S-specific epitopes targeted by antibodies induced by mRNA-1273 primary and variant-updated booster vaccination.</p></sec>