Vaccine breakthrough infection leads to distinct profiles of neutralizing antibody responses by SARS-CoV-2 variant
Michael S. Seaman, Mark J. Siedner, Julie Boucau, Christy L. Lavine, Fadi Ghantous, May Y. Liew, Josh Mathews, Arshdeep Singh, Caitlin Marino, James Regan, Rockib Uddin, Manish C. Choudhary, James P. Flynn, Geoffrey Chen, Ashley Stuckwisch, Taryn Lipiner, Autumn Kittilson, Meghan Melberg, Rebecca F. Gilbert, Zahra Reynolds, Surabhi Iyer, Grace Chamberlin, Tammy D. Vyas, Jatin M. Vyas, Marcia B. Goldberg, Jeremy Luban, Jonathan Z. Li, Amy K. Barczak, Jacob E. Lemieux
Abstract
Protective immunity against SARS-CoV-2 infection after COVID-19 vaccination may differ by variant. We enrolled vaccinated (n = 39) and unvaccinated (n = 11) individuals with acute, symptomatic SARS-CoV-2 Delta or Omicron infection and performed SARS-CoV-2 viral load quantification, whole-genome sequencing, and variant-specific antibody characterization at the time of acute illness and convalescence. Viral load at the time of infection was inversely correlated with antibody binding and neutralizing antibody responses. Across all variants tested, convalescent neutralization titers in unvaccinated individuals were markedly lower than in vaccinated individuals. Increases in antibody titers and neutralizing activity occurred at convalescence in a variant-specific manner. For example, among individuals infected with the Delta variant, neutralizing antibody responses were weakest against BA.2, whereas infection with Omicron BA.1 variant generated a broader response against all tested variants, including BA.2.