Mass COVID-19 vaccination and continued introduction of new SARS-CoV-2 variants
increased prevalence of hybrid immunity at various stages of waning protection. We …

Omicron Neutralization after Bivalent Vaccine Boost One or two monovalent vaccine
boosters showed a large decrease in neutralization activity against omicron subvariants …

After the global spread of the SARS-CoV-2 Omicron BA. 2, some BA. 2 subvariants,
including BA. 2.9. 1, BA. 2.11, BA. 2.12. 1, BA. 4, and BA. 5, emerged in multiple countries …

The newly emerged severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2)
variants with high transmission rates and striking immune evasion have posed a serious …

Vaccine protection against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)
infection wanes over time, requiring updated boosters. In a phase 2, open-label, randomized …

During the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic,
multiple variants escaping preexisting immunity emerged, causing reinfections of previously …

Objectives We aimed to compare the clinical severity of Omicron BA. 4/BA. 5 infection with
BA. 1 and earlier variant infections among laboratory-confirmed SARS-CoV-2 cases in the …

Summary Emerging SARS-CoV-2 sub-lineages like XBB. 1.5, XBB. 1.16, EG. 5, HK. 3 (FLip),
and XBB. 2.3 and the variant BA. 2.86 have recently been identified. Understanding the …

Background Despite the availability of effective vaccines against COVID-19, booster
vaccinations are needed to maintain vaccine-induced protection against variant strains and …

Background Although the COVID-19 pandemic has persisted for over 3 years, reinfections
with SARS-CoV-2 are not well understood. We aim to characterize reinfection, understand …