Highly-mutated “Pirola” COVID variant is spreading more rapidly, but vaccines seem to neutralize it


Four years ago, on November 30, 2019, the first confirmed case of COVID-19 was detected in a man in Wuhan, China. It would still be over a month before the SARS-CoV-2 virus was fully identified, but it would go on to kill no less than 7 million people globally and forever alter life on this planet.

As we have changed, so has the virus. It’s natural for pathogens to evolve workarounds to our immunity and, a few months ago, scientists detected a variant of SARS-CoV-2 that seemed alarmingly capable of infecting mass amounts of people, breaking through the immunity acquired from previous infections and vaccines.

The variant is named BA.2.86, nicknamed by some experts as “Pirola,” because a string of letters and numbers can be confusing to the general public. When Pirola first hit the radar of virus hunters, it was only responsible for a handful of cases. It was not really responsible for the wave of COVID infections that surged at the end of summer. But now that seems to be changing and Pirola is making a bigger impact as the pandemic heads into its fourth winter.

The WHO estimates “the public health risk posed by BA.2.86 is currently evaluated as low at the global level.”

Many experts who have been watching its evolution closely are worried about this trend. Two weeks ago, BA.2.86 accounted for an estimated 3 percent of coronavirus cases in the United States, according to the Centers for Disease Control and Prevention (CDC). However, the public health agency’s most recent report estimates it now makes up nearly 10 percent of cases and is the third most prevalent strain after EG.5 and HV.1.

The rise of the variant comes as a concern as various hotspots across the country are seeing more COVID-19 hospitalizations. On November 21, the World Health Organization labeled it a “variant of interest,” a tier below its “variant of concern” designation for truly infectious strains like Omicron and Delta. The WHO estimates “the public health risk posed by BA.2.86 is currently evaluated as low at the global level.”

Nonetheless, as the holidays ramp up, many are wondering what circulating COVID means for gatherings and public health, and just how concerned we should be.

When asked about the rise, Dr. T. Ryan Gregory, an evolutionary and genome biologist at the University of Guelph in Canada, told Salon he is “concerned,” but perhaps for the reasons people might not suspect. First, he said, he doesn’t think Pirola, or any other single variant, is likely to cause a massive wave like Omicron did in winter 2021 and 2022. In part because it’s not one variant that experts fear are behind waves, but instead a “soup of variants” that keep the number of infections and hospitalizations consistently high. This doesn’t necessarily overwhelm hospitals like what happened in the earlier days of the coronavirus pandemic, but it does keep putting pressure on an already vulnerable system. 

“In other words, it isn’t about ‘tsunamis” anymore — it’s about ‘high sea level,’” Gregory said. “And it does mean more long COVID [in which symptoms last for months or years], more variant evolution.”

BA.2.86 is not a new variant. Scientists first identified it from a single sequence in Israel over the summer. Soon after, two more were spotted in Denmark. Since then, it’s shown up all around the world. Pirola has caught the attention of scientists due to its peculiar mutations, specifically one that is similar to the “FLip mutation” in the virus’s spike protein. (The name FLip comes from a shift in two amino acids labeled F and L.) This specific mutation increases the chances of immune evasion to the disease, meaning a person can get reinfected because their immune system won’t recognize the virus again. 


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“BA.2.86 differed from its ancestor BA.2 by about 30 mutations in the spike protein and several other mutations in other gene regions,” Gregory explained. “Again, these changes accumulated over the span of about a year as the variant evolved within a host with a chronic infection.”

Gregory added this is another point of concern: that variants are evolving within people with chronic infections, so-called “recombinant variants” that likely produced variants like XBB.1.5 that dominated infections throughout most of 2023. The current crop of vaccines now available are tailored to fight XBB.1.5, which descended from Omicron.

Gregory said these variants can and do establish as evolving lineages in the larger population. “This means we need to take extra care to protect immunocompromised patients and others who may be most susceptible to long-term infections,” he said.

Dr. Rajendram Rajnarayanan, of the New York Institute of Technology campus in Jonesboro, Arkansas, told Salon he is also concerned about the rise in Pirola for other reasons. One being that the U.S. doesn’t have the tools it did in previous waves to properly monitor it.

“What I’m concerned about is that many things are hitting us together. Especially at a stage where the healthcare system is tremendously unprepared.”

For example, the CDC’s daily COVID-19 tracker, a once-revered source of information regarding the number of COVID-19 cases in the United States, no longer works. Instead, the CDC tracks hospital admissions and wastewater samples, which only accounts for 40 percent of the population. Every other week the CDC updates variant proportions, which is where recent data showing a rise in Pirola infections came from. The most recent update marked the first time BA.2.86 surged enough to be a standalone variant in the eyes of the CDC.

Rajnarayanan said the lack of masking is a concern to him as well, in addition to a COVID-19 wave hitting alongside other viruses. Seasonal influenza is increasing in parts of the country, and so are cases of RSV, another respiratory virus that mainly impacts children and elderly people. Meanwhile, cases of pneumonia known as “white lung” are cropping up in China, parts of Europe and a few states, such as Ohio.

“Am I concerned about COVID alone? Probably not, but at the same time, what I’m concerned about is that many things are hitting us together,” Rajnarayanan said. “Especially at a stage where the healthcare system is tremendously unprepared.” 

Symptoms with BA.2.86 are similar to what doctors have seen with other BA.2 variants. 

“But again, the issue is less about whether each new variant is worse than the worst,” Gregory emphasized. “But whether it will add more pressure on healthcare systems, lead to more long COVID and contribute to further viral evolution.”

The good news is that this doesn’t appear to be causing more severe acute illness. Both Rajnarayanan and Gregory said that the new vaccines likely work against this variant because BA.2.86 descended directly from the ancestral BA.2, too. This perspective is supported by a recent preprint study (meaning it is not yet peer-reviewed) that indicated the latest shots were able to neutralize the variants.

“Evidence indicates that these new boosters do work against more recent variants, including Eris clan (EG.5*) and Pirola clan (BA.2.86, JN.1),” Gregory said. “Of course, that requires that people actually get the boosters, and that they be made available for people to get, and even then what it protects against is mostly severe acute illness, and less so transmission or long COVID.”

Rajnarayanan said he doesn’t think the rise in the variant should totally scare people away from holiday gatherings, either. He advises that people should enjoy themselves, but also “be mindful” about what public health officials are saying in terms of recommendations and guidelines. 

“If people are obviously coughing, if you noticeably see something, of course do something about it,” he said. “Wear a mask, and stay away from it.”





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