There are already dozens of cases across almost half of the U.S. of a new Covid subvariant that’s even more contagious than the already highly transmissible omicron variant.
Nearly half of U.S. states have confirmed the presence of BA.2 with at least 127 known cases nationwide as of Friday, according to a global database that tracks Covid variants. The Centers for Disease Control and Prevention, in a statement Friday, said although BA.2 has increased in proportion to the original omicron strain in some countries,
it is currently circulating at a low level in the U.S. The subvariant is 1.5 times more transmissible than the original omicron strain, referred to by scientists as BA.1, according to Statens Serum Institut, which conducts infectious disease surveillance for Denmark.
The UK Health Security Agency has designated BA.2 a variant under investigation, saying it could have a growth advantage. Preliminary calculations suggest BA.2 could be 1.5 times more infectious than BA.1, Denmark’s top infectious disease authority, Statens Serum Institut (SSI), said in a note on Wednesday. However, an initial analysis by the institute showed no difference in the risk of hospitalization for BA.2 compared to BA.1.
“There is some indication that it is more contagious, especially for the unvaccinated, but that it can also infect people who have been vaccinated to a greater extent,” SSI’s technical director Tyra Grove Krause said at the briefing. This could mean the peak of Denmark’s epidemic will extend a bit further into February than previously forecast, Krause said. BA.2 cases have also been registered in Britain, Sweden, and Norway, but to a much lesser extent than in Denmark.
