The BA.2 virus – a subvariant of the Omicron coronavirus variant – isn’t just spreading faster than its distant cousin, it may also cause more severe disease and appears capable of thwarting some of the key weapons we have against Covid-19, new research suggests.
New lab experiments from Japan show that BA.2 may have features that make it as capable of causing serious illness as older variants of Covid-19, including Delta.
And like Omicron, it appears to largely escape the immunity created by vaccines. A booster shot restores protection, making illness after infection about 74% less likely.
BA.2 is also resistant to some treatments, including sotrovimab, the monoclonal antibody that’s currently being used against Omicron.
The US Centers for Disease Control and Prevention is keeping close watch on BA.2, said its director, Dr. Rochelle Walensky.
“There is no evidence that the BA.2 lineage is more severe than the BA.1 lineage. CDC continues to monitor variants that are circulating both domestically and internationally,” she said Friday. “We will continue to monitor emerging data on disease severity in humans and findings from papers like this conducted in laboratory settings.”
BA.2 is highly mutated compared with the original Covid-causing virus that emerged in Wuhan, China. It also has dozens of gene changes that are different from the original Omicron strain, making it as distinct from the most recent pandemic virus as the Alpha, Beta, Gamma and Delta variants were from each other.