BA.1

The Omicron variants BA.1 and BA.2 of the SARS-CoV-2 virus, which dominated from about December to April, can already circumvent after three months the protection against infection offered by vaccinations and recovery from infection. This…

People infected with the earliest version of the Omicron variant of the coronavirus, first identified in South Africa in November, may be vulnerable to reinfection with later versions of Omicron even if they have been vaccinated and…

The disclosure of new Covid variants emerging in China and the rise of a potentially more transmissible strain in the U.K. has recast the spotlight on the ongoing risk of the virus, even as health experts say there’s no reason…

With signs of the COVID-19 Omicron wave having peaked in parts of the world, including Canada, scientists are keeping a close eye on a subvariant that is rapidly spreading in some countries. The BA.2 sub-lineage of Omicron,…