A new COVID variant nicknamed "Pirola" has been detected in Australia after sparking a sped-up vaccination program in the United Kingdom.
A new variant in itself is not unusual — viruses evolve and change over time, and new mutated versions pop up frequently.
However, this one caught the attention of scientists.
According to the British Medical Journal, Pirola appears to have evolved from the Omicron subvariant BA.2, which was widely circulating in early 2022.
One case has been detected in Australia, in a laboratory in Western Australia, genomic sequencing data shows.
However, there could be more out there because only a fraction of all COVID-19 infections get submitted to for testing.
WA's health department said the case in Australia was "closely related – without significant differences – to those BA.2.86 strains reported from other countries".
The World Health Organization labelled BA.2.86 a "variant under monitoring" — which means they're keeping a close eye on it — in mid-August.
It has not been formally called a "variant of concern" yet or given a Greek name like Omicron or Delta.
Pirola is an informal nickname the variant received on social media from a community who track COVID variants.
While new variants emerge all the time, scientists became interested in this one because of how mutated it was compared to its predecessor.
It has 33 changes to its spike proteins — the pointy part of the virus that infects human cells — compared to BA.2, analysis from China found.
To put that into context, that's the same magnitude of changes that made Omicron so distinct from the Delta variant which dominated the world in late 2020, the US Centers for Disease Control said.
It's also a degree of change you'd normally see over several generations of a virus, rather than in one fell swoop, Kirby Institute virologist Stuart Turville said.
"I call them [variants like BA.2.86] 'parachutes' — they kind of land and appear out of the middle of nowhere," Professor Turville said.
There are a few theories for where it came from, but most scientists agree that it likely evolved over several months in someone with a chronic infection, University of New South Wales applied mathematician James Wood said.
Despite all the mutations, scientists say BA.2.86 so far does not appear to be behaving too differently to other variants.
There have been no reports that it causes different symptoms to previous variants, Africa's Centre for Disease Control said.
There has also been no evidence that BA.2.86 causes increased transmission or a greater risk of severe disease and hospitalisation, it said.
Source: World Health Organization
The degree of mutations the virus carried worried many scientists when it first emerged, due to fears it could find it easier to evade immunity from vaccines or previous infections.
But recent research, which hasn't been peer-reviewed yet, has been reassuring:
Epidemiologist Catherine Bennett said even though it was becoming clearer that BA.2.86 had compromised ability to infect people and was less likely to become the next dominant variant, it was still important to "watch and wait".
"It's not just about what this variant does and how it might impact us … it's also the bigger picture," Professor Bennett said.
"What could this mean for our future, if this [variant] builds a new viral genome platform on which more mutations can accumulate? Where does that take the virus and what does that mean for us?"
Professor Wood said while some of BA.2.86's mutations did not appear to make it better at spreading, that could change as it evolved.
"This, I think, is something we definitely want to keep an eye on," he said.
"But right now, I don't think it changes our risk perception."
The United Kingdom brought its vaccination program for vulnerable groups and healthcare workers forward by one month, over concerns about the variant.
However in Australia, the federal government said the latest advice on vaccinations — which is to get up to date with booster shots — still applied.
WA's health department encouraged people to remain vigilant about COVID-19 and other viruses.
"People are encouraged to stay home if they are sick, wash or sanitise their hands regularly, cover coughs, and, importantly, get vaccinated against COVID-19 and influenza," it said in a statement.
"Keeping up to date with vaccinations remains the best way to prevent serious disease and hospitalisation from COVID."
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