Worldwide, millions of persons have received multiple COVID-19 vaccinations and subsequently recovered from SARS-CoV-2 Omicron breakthrough infections. In 2 small, matched cohorts (n = 12, n = 24) in Denmark, we found Omicron BA.1/BA.2 breakthrough infection after 3-dose BNT162b2 vaccination provided improved Omicron BA.5 neutralization over 3-dose vaccination alone.
Keywords: BA.1; BA.2; BA.5; COVID-19; Omicron; SARS; SARS-CoV-2; coronavirus; coronavirus disease; respiratory infections; severe acute respiratory syndrome coronavirus 2; vaccines; viruses; zoonoses.