With the continuation of the pandemic, many severe acute respiratory syndrome coronavirus
2 (SARS-CoV-2) variants have appeared around the world. Owing to a possible risk of …

Background: From the start of the COVID-19 pandemic, new SARS-CoV-2 variants have
emerged that potentially affect transmissibility, severity, and immune evasion in infected …

The emergence and rapid spread of SARS-CoV-2 variants may affect vaccine efficacy
substantially. The Omicron variant termed BA. 2, which differs substantially from BA. 1 based …

Some variants of SARS-CoV-2 are associated with increased transmissibility, increased
disease severity or decreased vaccine effectiveness (VE). In this population-based cohort …

OBJECTIVES There is limited evidence on whether the relative severity of coronavirus
disease 2019 (COVID-19) in children and adolescents differs for different severe acute …

New SARS-CoV-2 may pose problems in controlling the COVID-19 pandemic for public
health. We aimed to assess and compare the symptoms and severity of cases due to the …

The emergence of SARS-CoV-2 variants of concern (VOC) is driven by mutations that
mediate escape from neutralizing antibodies. There is also evidence that mutations can …

Background COVID-19 vaccines have been crucial in the pandemic response and
understanding changes in vaccines effectiveness is essential to guide vaccine policies …

The emergence and rapid spread of SARS-CoV-2 variants may impact vaccine efficacy
significantly. The Omicron variant termed BA. 2, which differs genetically substantially from …

Objectives To estimate the risk of hospitalization among reported cases of the Delta variant
of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) compared with the Alpha …