COVID 'Pirola': Scientists track 'highly mutated' variant – what we know

Scientists are now scrambling to find out more about the new BA.2.86 strain. Here's what we know so far.

Coronavirus molecule
It's still too early to tell the full impact of BA.2.86, but scientists are on alert. (Getty Images)

What's happening?

The new Pirola COVID variant is spreading in "most regions in the UK", according to the latest government update.

The BA.2.86 variant has already been detected in countries across the world and is now thought to be spreading fast throughout the UK.

In its latest variant technical briefing, the UK Health Security Agency (UKHSA) said BA.2.86 "continues to transmit within the UK, with sporadic cases identified in most regions".

The strain, which is confirmed to have more than 30 mutations, is now believed to be becoming the most dominant in the UK.

BA.2.86 has already been detected in Switzerland and South Africa in addition to Israel, Denmark, the US and the UK, according to the World Health Organization (WHO).

The US Centers for Disease Control and Prevention (CDC) has also warned that the subvariant may have a higher potential for causing infections in those who have previously contracted the virus or received vaccination.

COVID cases have been on the rise globally, with the WHO previously warning about another variant known as EG.5 or “Eris”. The Zoe Health Study, led by King's College London researchers, now predicts that more than a million people in the UK have symptomatic COVID-19.

In the worst-case scenario, scientists warn there could be "a big new wave of infections", with some countries announcing autumn boosters in an attempt to subdue a potential surge in infections.

Here, Yahoo News UK explains what you need to know about the recently discovered COVID strain.

What is BA.2.86 and why is it nicknamed 'Pirola'?

Little is known about the newly discovered BA.2.86 strain, although one thing that is concerning scientists is its large number of mutations.

Maria Van Kerkhove, an epidemiologist at the World Health Organisation (WHO), said it needs "closer monitoring", tweeting: "Surveillance, sequencing & #COVID19 reporting [are] critical to track known/detect new variants."

Scientists are concerned about the high number of mutations because it could boost the virus's ability to adapt, potentially making it both more infectious and resistant to vaccines.

As for its nickname, Pirola, we've already had Omicron, and as the WHO are now only assigning Greek letters to variants of concern, someone has made an amalgamation of Pi and Rho, which are next in the Greek alphabet.

The latest variant technical briefing said early data indicated that BA.2.86 is no more likely to evade existing antibodies than XBB.1.5, another variant that has been circulating widely in the UK.

Where has it been detected?

BA.2.86 was first detected in Denmark on 24 July, with a second case picked up on 31 July. That same day, it was discovered in Israel.

Another case of the strain was picked up in the US earlier this month, with a third case recorded in Ohio this week, while the UK detected its first known case in London on Friday last week.

Of course, this doesn't mean these are the only countries Pirola is confined to – it is most likely in others, too – but many countries have wound back their genomic surveillance, making it hard to tell where else it might be.

None of the cases appear to be linked, and the UKHSA said the UK case was a person with no recent travel history, suggesting a degree of community transmission within the country.

How serious is Pirola?

In short, we don't know yet but the government's variant technical briefing said: "While the available data remains limited, there is currently no evidence to suggest that BA.2.86 infection is more likely to make people seriously ill than currently-circulating variants, while vaccination is likely to provide continued protection."

The CDC previously said that BA.2.86 may be more capable than older variants in causing infection in people who previously had COVID-19 or received vaccines.

It added that it was too soon to know whether it might cause more severe illness than previous variants.

Francois Balloux, director of the UCL Genetics Institute at University College London, said the new strain is “the most striking SARS-CoV-2 strain the world has witnessed since the emergence of Omicron” with more than 30 mutations.

As UCL's Clinical Operational Research Unit's Professor Christina Pagel put it: "Still plenty of potential for it to be a nothingburger but plausible *worst* case is a big new wave of infections with no intrinsic increased severity. Things will become clearer over next 7-14 days."

According to an article in the respected Nature publication, Jesse Bloom, a viral evolutionary biologist at the Fred Hutchinson Cancer Center in Seattle, thnks there is limited cause for concern.

“I don’t think anybody needs to be alarmed by this,” he said. “The most likely scenario is that this variant fizzles out, and in a month, nobody other than people like me even remember that it existed.”

Nature does acknowledge, however, that researchers are "racing" to track if the new strain will be of "global concern".

What has the CDC said?

The CDC said on Wednesday the new BA.2.86 lineage of coronavirus may be more capable than older variants in causing infection in people who have previously had COVID-19 or who have received vaccines.

It said it was too soon to know whether this might cause more severe illness compared with previous variants.

But due to the high number of mutations detected in this lineage, there were concerns about its impact on immunity from vaccines and previous infections, the agency said.

The Omicron offshoot carries more than 35 mutations in key portions of the virus compared with XBB.1.5, the dominant variant through most of 2023 – a number roughly on par with the Omicron variant that caused record infections compared to its predecessor.

Read more: BA.2.86 subvariant potentially better at causing breakthrough infections: CDC (The Hill, 2 mins)

What if I've already had the COVID vaccine?

The CDC said due to the high number of mutations detected in this lineage, there were concerns about its impact on immunity from vaccines.

Prof Balloux said most people will have some immunity because they've either previously had COVID or have been vaccinated for it, but this is no guarantee.

Professor Rowland Kao, an epidemiologist at the University of Edinburgh, told the Guardian that the "bulk of vaccinations have now been some time ago, and even the most vulnerable are likely approaching the point where immune protection is fading".

He pointed to increase in COVID hospital admissions, although it's not known if this is due to Pirola, and warned that seasonal factors and the "usual combination of autumn return to school and university and work" could help spread the strain.

BA.2.86 stems from an "earlier branch" of COVID, so it differs from the variant targeted by current vaccines, explained Dr S Wesley Long, medical director of diagnostic microbiology at Houston Methodist Hospital. Although it is still unclear if it will gain a competitive advantage over rival strains.

What are different countries doing about BA.2.86?

With this additional risk of infection in mind, Europe is set for "natural experiment" of vaccination policy, with France offering a free autumn booster free to everyone who wants one, Prof Pagel said.

She added that the UK is taking a slightly different approach, restricting the offer mainly to people aged 65 and above.

Even at a local level, authorities have been taking notice of the strain's discovery, with Buckinghamshire Council's cabinet member for health and wellbeing Angela Macpherson telling residents: "As expected, the coronavirus continues to mutate, and worldwide surveillance continues to identify new variants.

“Over the year levels of COVID in the community and therefore hospital admissions will fluctuate from time to time. The World Health Organization says there are currently no circulating variants of concern and there is no evidence that the new variants cause more severe disease."

Meanwhile in the US, Joe Biden's government are trying to speed up the process of finalising contracts so pharmacies like CVS and Walgreens can offer free jabs to the uninsured as early as mid-September.

The CDC is keeping an eye on the BA.2.86 lineage because it has 36 mutations that distinguish it from the currently-dominant XBB.1.5 variant.

The US agency, however, said virus samples are not yet broadly available for more reliable laboratory testing of antibodies.