British health chiefs are now officially keeping tabs on a version of Omicron that is harder to track amid fears it may have spread to thousands of people.
The UK Health Security Agency today marked BA.2 as a ‘variant under investigation’.
The category is reserved for variants that are spreading in the UK and are likely more transmissible and better able to evade vaccines than other strains.
It falls just one step below a ‘variant of concern’, a title listed for mutant lineages like Omicron, Delta and Alpha. But UKHSA bosses could still decide to place BA.2 in the highest category if the strain poses a greater threat.
Some 426 cases have already been confirmed in the UK so far, but only a fraction of infections are checked for variants. It means the true toll could be ten times higher.
It carries many of the same mutations as Omicron, as well as other quirks that have seen it dubbed a ‘stealth’ variant.
Variant-tracking scientists said preliminary data suggests BA.2 could be even more transmissible than Omicron, although there is no reason to say it would cause more severe disease.
Dr Tom Peacock, one of the first virologists to raise the alarm over Omicron, poured cold water over concerns about BA.2, insisting it was unlikely to have a ‘substantial impact’ on the current wave.
But he warned it could still replace BA.1 – the original version of Omicron – over the coming months.
Health Secretary Sajid Javid today insisted the country was ‘learning to live with this virus’, and praised the UK’s ‘world-leading surveillance system’ for being able to spot and carefully monitor any genetic changes to Covid.
Around 8,000 cases have been detected in 40 different countries, with the strain dominant across parts of India and the Philippines. BA.2 infections are also rising in Denmark and Germany.
The above figures — from the UK’s largest Covid surveillance centre — show the locations where BA.2 has been detected in the UK
Pictured above are all the countries where BA.2 has been spotted. Cases are growing in Denmark, Germany and the UK, and it is already dominant in parts of India and the Philippines
Pictured above is the estimated number of BA.2 cases in the UK according to one of Britain’s largest Covid surveillance centres, the Sanger Institute. The UK is currently only checking about 10 per cent of infections for variants because of the large outbreak
The UKHSA announced that it had classed BA.2 as being a variant under investigation in a tweet, but this was later hastily deleted.
The agency revealed more details in its weekly technical briefing on the state of the variant situation across the UK, which was published tonight.
An offshoot of the Delta variant, which was dominant before Omicron burst onto the scene, is also on the UKHSA’s ‘variant under investigation’ list, alongside ‘Mu’.
The World Health Organization says there are three Omicron lineages (BA.1, BA.2 and BA.3), but only BA.2 appears to be outpacing the original strain.
The UKHSA today said it is not possible to determine where it originated yet.
The agency said the proportion of cases made up by BA.2 was still ‘low’, revealing it had detected the strain 426 times.
London (146) and the South East (97) have seen the most cases so far.
Britain’s explosion of Omicron was fairly easy to track because of one of the variant’s specific quirks – a deletion of its spike ‘S’ gene.
It meant the strain could be detected on widely-used PCR tests without the need for lengthy laboratory analysis, known as genome sequencing.
The deletion allowed Omicron samples to stand out from other strains circulating at the time, including Delta, simply because they did not cause the same PCR ‘S-gene target failure’ effect.
But this does not appear to be the case with BA.2.
PCR tests will still spot if someone with BA.2 has Covid.
However, BA.2 samples will need to be sent for further lab analysis to determine if someone caught that exact lineage.
Original Omicron samples are also still passed on, as part of the UK’s pioneering surveillance scheme.
Scientists have suggested, however, that there is no need to be overly concerned about the strain.
Dr Peacock, from Imperial College London, said: ‘I would be very surprised if BA.2 caused a second wave at this point.
‘Even with slightly higher transmissibility this absolutely is not a Delta to Omicron change, and instead is likely to be slower and more subtle.
‘That said, I would not be surprised if BA.2 slowly replaces (Omicron) over the coming months with a slightly more “optimised” mutations.’
He added: ‘Very early observations from India and Denmark suggest there is no dramatic difference in severity compared to (Omicron).
‘This data should become solid, one way or another, in the coming weeks.
‘I would also agree that there is likely to be minimal differences in vaccine effectiveness against (Omicron) and BA.2. It’s relatively likely.’
Professor Francois Balloux, a geneticist at University College London, said he would not treat BA.2 separately from Omicron.
‘I recommend to anyone not obsessed with (Covid) variant minutiae to consider both as “Omicron”, unless evidence emerged that there might be a meaningful (disease) difference between the two.’
UKHSA’s Covid incident director Dr Meera Chand said an altered form of Omicron was not unexpected because viruses are constantly evolving and mutating.
She said: ‘It is the nature of viruses to evolve and mutate, so it’s to be expected that we will continue to see new variants emerge as the pandemic goes on.
‘Our continued genomic surveillance allows us to detect them and assess whether they are significant.
‘So far there is insufficient evidence to determine whether BA.2 causes more severe illness than BA.1, but data is limited and UKHSA continues to investigate.
‘Case rates remain high throughout the UK and we must remain vigilant and take up vaccinations. We should all continue to test regularly with LFDs and take a PCR test if symptoms develop.’
Mr Javid said: ‘We are learning to live with this virus – and thanks to our world-leading surveillance system we can rapidly detect and carefully monitor any genetic changes to Covid.
‘Our exceptional vaccine rollout means the number of people severely affected by Covid is low, and the UK’s innovation and research has discovered life-saving treatments for those most at-risk from Covid.
‘As we cautiously return to Plan A, I encourage you to give yourself and your loved ones the best protection possible and Get Boosted Now.’
SAGE scientists have warned that another variant may emerge in the coming months that could be even more transmissible than Omicron.
Some expect the virus to mutate to spread quicker, but be less able to cause severe disease.
It came as the latest Covid surveillance showed cases are already rising among primary school children in England in what could be a sign of the back-to-school effect.
Statisticians at the Office for National Statistics estimated eight per cent of youngsters aged two to 11 had Covid on any given day in the week to January 15, the equivalent of one in 13, up slightly from 7 per cent the week prior.
The rate, based on swabs taken from 160,000 people across the country, is the highest of all other age groups, with 20 to 34-year-olds having the next highest rate (one in 17).
While rates are falling or flatlining in every other age group they are still climbing in children. Just five per cent of under-12s were thought to have the virus a month earlier.
Children returned to classrooms on January 4 after a two-week break over the festive period.
Despite the rising infections in primary school and nursery-aged children, the ONS found that infections fell across England for the first time since Omicron took off last week.
It estimated around 2.9million people were infected on any given day in the week to January 15, a ‘welcome decrease’ from the record 3.7m the previous week.
The ONS survey is regarded as the most reliable indicator of the UK’s outbreak because it uses random sampling of around 100,000 people, rather than relying on people coming forward to be tested.