Background The global surge in the omicron (B. 1.1. 529) variant has resulted in many
individuals with hybrid immunity (immunity developed through a combination of SARS-CoV …

Since the outbreak of the coronavirus disease 2019 (COVID-19) pandemic, there have been
a few variants of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), one of …

First infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is
associated with increased risk of acute and postacute death and sequelae in various organ …

The first dominant SARS‐CoV‐2 Omicron variant BA. 1 harbours 35 mutations in its Spike
protein from the original SARS‐CoV‐2 variant that emerged late 2019. Soon after its …

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) breakthrough infections in
vaccinated individuals and reinfections in previously infected individuals have become …

Immunological memory is the basis of protective immunity provided by vaccines and
previous infections. Immunological memory can develop from multiple branches of the …

Protective Effect of Previous SARS-CoV-2 Infection against Omicron BA.4 and BA.5 Subvariants |
New England Journal of Medicine Skip to main content The New England Journal of Medicine …

We provide two methods for monitoring reinfection trends in routine surveillance data to
identify signatures of changes in reinfection risk and apply these approaches to data from …

Epidemiologic surveillance has revealed decoupling of Coronavirus Disease 2019 (COVID-
19) hospitalizations and deaths from case counts after emergence of the Omicron (B. 1.1 …

Abstract SARS-CoV-2 Omicron BA. 1 and BA. 2 subvariants are genetically divergent. We
conducted a matched, test-negative, case-control study to estimate duration of protection of …