Background Despite the high efficacy of the BNT162b2 messenger RNA vaccine against
severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), rare breakthrough …

Vaccine breakthrough SARS-CoV-2 infection has been monitored in 3720 healthcare
workers receiving 2 doses of BNT162b2. SARS-CoV-2 infection is detected in 33 subjects …

Background SARS-CoV-2 vaccines are highly effective at preventing COVID-19-related
morbidity and mortality. As no vaccine is 100% effective, breakthrough infections are …

Resurgence of Covid-19 in Vaccinated Health Workers From March through July 2021, a
total of 227 health care workers at UCSD, 57% of whom were fully vaccinated, tested …

Background: The research aimed to investigate the incidence of SARS-CoV-2 breakthrough
infections and their determinants in a large European cohort of more than 60,000 health …

Background Data on breakthrough SARS-CoV-2 Delta variant infections in vaccinated
individuals are limited. Methods We studied breakthrough infections among Oxford …

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies decay but
persist 6 months postvaccination; lower levels of neutralizing titers persist against Delta than …

Serological surveys have been conducted to establish prevalence for COVID-19 antibodies
in various cohorts and communities, reporting a wide range of outcomes. The prevalence of …

Background The relationship between the presence of antibodies to severe acute
respiratory syndrome coronavirus 2 (SARS-CoV-2) and the risk of subsequent reinfection …

Antibody responses to SARS-CoV-2 can be detected in most infected individuals 10–15 d
after the onset of COVID-19 symptoms. However, due to the recent emergence of SARS …