Will BA.2.86 (‘Pirola’), the New Coronavirus Variant, Increase COVID-19 Cases? > News > Yale Medicine

Because BA.2.86 has so many mutations that make it different from other coronavirus strains, many medical experts wonder if it has the potential to bypass immune defenses both from natural infection and prior vaccination, Dr. Roberts explains.

“Nobody knows right now, but studies are ongoing,” he says. “The biggest concern has been the number of mutation differences with BA.2.86. When we went from XBB.1.5 to EG.5, that was maybe one or two mutations, and they were expected. With every respiratory virus, as it spreads from person to person, it evolves gradually over time. But these massive shifts, which we also saw from Delta to Omicron, are worrisome.”

The flu, Dr. Roberts points out, similarly sometimes has a massive change, such as with the swine flu in 2009. However, sometimes these variants fade away and don’t amount to anything, he adds.

“The big question is if BA.2.86 will have the same exponential growth that Omicron did—in terms of case numbers—or if it will die out, which is certainly what everyone hopes,” Dr. Roberts says.

As of Aug. 30, the CDC reports that the variant has been identified in at least four states in the U.S. in samples from either people or wastewater.

The good news is that, thanks to the greater degree of herd immunity from infection and vaccination, the world is not as vulnerable to severe illness or infection from the coronavirus as it was in 2020, Dr. Roberts explains.

“Since the original version of SARS-CoV-2, many people have gotten infected, and many have been boosted,” he says. “However, for many of us, it might have been a year or more since we’ve had a booster, so I would encourage everyone to get the updated shot, which is expected to come out in mid-September.”