US lab tests suggest new Covid-19 variant BA.2.86 may be less contagious, less immune-evasive than feared

Two teams of US scientists have completed lab experiments testing the antibodies from vaccinated and infected Americans to see how well they might be able to fend off currently circulating variants of the virus that causes Covid-19, including the highly mutated BA.2.86.

Their results match up almost exactly, and the news – at least when it comes to BA.2.86, which has also been dubbed Pirola – is very good. Our immune systems can recognise and fight off this variant as well as, and perhaps even a bit better than, the currently circulating offshoots of the XBB variant, according to CNN.

What’s more, people who had the most robust responses against BA.2.86 were those who were within six months of an infection with the XBB subvariant. This suggests that this fall’s updated Covid-19 vaccines, which are designed to fight off XBB.1.5, will provide added protection against a range of circulating Covid-19 lineages, including BA.2.86.

“Two independent labs have basically shown that BA.2.86 essentially is not a further immune escape compared with current variants,” Dr. Dan Barouch, director of the Center for Virology and Vaccine Research at Beth Israel Deaconess Medical Centre and leader of one of the labs, told CNN.

Their results align with earlier experiments by labs in China and Sweden. Taken together, the data suggests that BA.2.86 will not be as troublesome as experts had feared. In short, this one seems to be a “scariant.”

But another variant, FL.1.5.1, which is causing an estimated 15 per cent of new Covid-19 infections in the US, may be a different story. This fast-growing descendant of the XBB recombinant variant has a constellation of mutations that have raised the eyebrows of variant trackers. In lab testing, it was the most immune-evasive.

“If there wasn’t so much hype about BA.2.86, that would actually be the focus of the paper,” Barouch said.