it scary time—again.
A new branch of Omicron, BA.2.86—called Pirola—has appeared in Israel, the US, South Africa, and the UK after it was first recorded in Denmark in late July. Pirola initially set off alarm bells because it was found in four countries at the same time—and because, with our viral surveillance systems heavily restricted, we didn’t know what it has been around for a long time. In addition, the sheer number of mutations it has is reason enough to fear – BA.2.86 has more than 30 new mutations, compared to the latest dominant variant, XBB.1.5.
“The only other time we’ve seen such a large genetic shift was the first shift from Delta to Omicron, which led to the most hospitalizations and the most deaths of any pandemic outbreak, ” said Dan Barouch, head of vaccine research. division of Beth Israel Deaconess Medical Center in Boston. As a result, scientists around the world are scrambling to determine whether BA.2.86 is something to worry about.
Early studies suggest that Pirola is no better at evading immunity than previous variants, despite all its mutations. The protection offered by vaccines should continue, and if you have been naturally exposed to the XBB variant, you should be better prepared to fight this new variant.
Why is Pirola not so good at avoiding immunity, despite having undergone many mutations? It likely evolved from BA.2, an older, more familiar form of Sars-CoV-2 that no longer circulates, meaning that Pirola is less resistant to neutralization than the newer variants, such as XBB.1.5. But it’s possible the variant could continue to evolve and change, Barouch warns, so staying vigilant will be key.
Determining whether it will disappear and become the dominant form of the virus in circulation will require a “wait-and-see” approach, Barouch added. “However, it doesn’t appear to be spreading at the same speed as, say, the original BA.1 or BA.5,” he said, referring to two of the Omicron variants that spread quickly.
Anna Bershteyn, an assistant professor and colead of the Covid modeling team at the NYU Grossman School of Medicine, agrees: so far, very reassuring. “As far as we know, it doesn’t seem like it’s going to be one of those big waves of hospitalizations and deaths, the kind that overwhelmed the health system in the first epidemic waves.”
In the UK, a nursing home in the east of England was invaded by the variant: 33 residents got Covid, with 28 definitely infected with BA.2.86-suggesting that it can be easily transmitted. But only two hospitalizations were reported, indicating that Pirola does not cause more severe disease than existing variants.
In some parts of the world, its appearance has sparked action in the form of accelerated stimulus programs. In the UK, the booster kick-off has been rescheduled from October to the following weeks. In the US, the latest round of boosters is expected to be approved by the Food and Drug Administration soon (although who will get them remains a source of debate). Findings in a recent preprint suggest that Moderna’s XBB.1.5 booster seems to work well against the BA.2.86 variant.
But while BA.2.86 is not yet widespread, a Covid wave is indeed unfolding, with cases on the rise as well. In the US, hospitalizations are up, although they are nowhere near the sky-high levels of this time last year. Cases are also mushrooming in the UK and Europe.
At the moment, the spread of BA.2.86 has become unlike the Omicron wave that rocketed around the world at the end of 2021—the last time we saw such a large raft of Covid mutations appear. As one scientist put it, Pirola could be a “real no burger.”
