Seroprevalence surveys suggest that more than a third and possibly more than half of the
global population has been infected with SARS-CoV-2 by early 2022. As large numbers of …

Summary Infection with SARS‐CoV‐2, the etiology of the ongoing COVID‐19 pandemic, has
resulted in over 450 million cases with more than 6 million deaths worldwide, causing global …

Background Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)
provides natural immunity against reinfection. Recent studies have shown waning of the …

Background The duration and effectiveness of immunity from infection with and vaccination
against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are relevant to …

During May–November 2021, case and hospitalization rates were highest among persons
who were unvaccinated without a previous diagnosis. Before Delta became the predominant …

Background There is a paucity of data on vaccine-induced or infection-induced (hybrid or
natural) immunity against omicron (B. 1.1. 529) subvariant BA. 2, particularly in comparing …

It is not too late to achieve global covid-19 vaccine equity Page 1 It is not too late to achieve
global covid-19 vaccine equity Gavin Yamey and colleagues say that a new, urgent push for …

Background BNT162b2 mRNA and ChAdOx1 nCOV-19 adenoviral vector vaccines have
been rapidly rolled out in the UK from December, 2020. We aimed to determine the factors …

Importance The Omicron variant is phylogenetically and antigenically distinct from earlier
SARS-CoV-2 variants and the original vaccine strain. Protection conferred by prior SARS …

Background The aim was to evaluate the necessity of coronavirus disease 2019 (COVID-19)
vaccination in persons with prior COVID-19. Methods Employees of the Cleveland Clinic …