In late 2020, after circulating for almost a year in the human population, severe acute
respiratory syndrome coronavirus 2 (SARS-CoV-2) exhibited a major step change in its …

Importance An overall household secondary attack rate (SAR) of 18.9%(95% CI, 16.2%-
22.0%) through June 17, 2021 was previously reported for SARS-CoV-2. Emerging variants …

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant of
concern comprises several sublineages, with BA. 2 and BA. 2.12. 1 having replaced the …

ABSTRACT The highly mutated BA. 2.86, with over 30 spike protein mutations in
comparison to Omicron BA. 2 and XBB. 1.5 variants, has raised concerns about its potential …

Background After the first COVID-19 wave caused by the ancestral lineage, the pandemic
has been fueled from the continuous emergence of new SARS-CoV-2 variants …

Objectives Vaccine effectiveness against transmission (VET) of SARS-CoV-2-infection can
be estimated from secondary attack rates observed during contact tracing. We estimated …

Vaccination programs against SARS-CoV-2 constitute the mainstay of public health
interventions against the global COVID-19 pandemic. Currently available vaccines have …

Despite widespread mass rollout programs, the rapid spread of the SARS-CoV-2 Omicron
variant called into question the effectiveness of the existing vaccines against infection …

The Omicron variant rapidly became the dominant SARS‐CoV‐2 strain in South Africa and
elsewhere. This review explores whether this rise was due to an increased transmission of …

The emerging SARS-CoV-2 variants of concern (VOCs) may display enhanced
transmissibility, more severity and/or immune evasion; however, the pathogenesis of these …