The UK Health Security Agency (UKHSA) has identified two new Covid-19 variants circulating in England, named BQ.1 and XBB. Both appear to come from the Omicron variant.
“A number of Omicron variants are currently circulating in England, many of which have acquired mutations which may produce a degree of immune escape,” the agency said. “Omicron sublineages BQ.1 and XBB have been given UKHSA variant designations to facilitate continued studies.”
BQ.1 is a sub-lineage of the previous Omicron variant, BA.5. It has been “designated on the basis of rapid growth”, the UKHSA said.
XBB, meanwhile, is what’s known as a “recombinant lineage”, meaning it derives from two previous Omicron sublineages. It has been already been found in 17 countries.
The variant may be a factor in the recent spike in cases in Singapore. So far, it has successfully evaded drug therapies and vaccines by working around the body’s immune system – potentially making it a more potent strain than its predecessors.
But, the most damaging element of this sub-variant is that scientists expect it will be just one of many which could emerge at the same time this winter.
XBB is causing concern among scientists after being detected in Europe, Asia and Australia.
XBB is spreading rapidly in Singapore in particular, having pushed Covid cases from 4,719 on October 9, to 11,732 on October 10, according to data from Johns Hopkins’ Coronavirus Resource Centre.
However, the country expects this wave to be “short and sharp”, averaging at around 15,000 daily cases by mid-November – although it could peak at around 20,000 on some days.
Previously BA.5 was the dominant variant in the UK, nearly 78.7% of confirmed cases in England were BA.5 which was first identified in April and was designated as a Variant of Concern on May 18.
Both new variants are not a cause for concern for some scientists. “It is not unexpected to see new variants of SARS-CoV-2 emerge. Neither BQ.1 nor XBB have been designated as Variants of Concern and UKHSA is monitoring the situation closely, as always,” Dr Meera Chand, Director of Clinical and Emerging Infection at UKHSA said.
Chand continued: “Vaccination remains our best defence against future COVID-19 waves, so it is still as important as ever that people come take up all the doses for which they are eligible as soon as possible.”
While early signs suggest it is more resistant to antibody treatments, the world is starting to create more boosters which broader protection, by producing vaccines with half the original vaccine and half protection against the dominant strains BA.4 and BA.5.
Lead respiratory virus immunology specialist Natalie Thornburg at the US Centres for Disease Control and Prevention, also said in a webinar this week: “XBB is a chimera. I think there have been a couple of sequences identified in the US. But it’s way, way, way, way below that 1% threshold. I mean, it’s really like a handful of sequences.”