Coronavirus strain JN.1 has been classified as a “variant of interest” but officials say it does not pose much threat to public health.
The World Health Organisation on Tuesday said that, on current evidence, the risk from the variant was “low”.
JN.1 was previously classified as a variant of interest as a part of its parent lineage to the Omicron variant, BA.2.86.
The United Nations agency said current vaccines continue to protect against severe disease and death from JN.1 and other circulating variants of the Covid virus.
The US Centers for Disease Control and Prevention (CDC) earlier this month said that the subvariant JN.1 makes up about an estimated 15 per cent to 29 per cent of cases in the United States as of 8 December, according to the agency’s latest projections.
The CDC also said ther was currently no evidence that JN.1 presents an increased risk to public health relative to other currently circulating variants and an updated shot could keep Americans protected against the variant.
JN.1 was first detected in Luxembourg in August, before spreading to the US, UK, France and other countries.
Last week, China detected seven infections of the Covid subvariant.
Covid cases are on the rise again in England. The were 5,975 confirmed cases in England in the seven days up to 9 December, according to the most recently available data.
This was an increase of 39 per cent, according to the UK government’s figures. However, the true number of cases could be far higher after mandatory testing regimes were scrapped last year.
It is not yet known exactly how many of those cases were JN.1.
Some 97,904 symptomatic Covid-19 Omicron cases were reported across the UK as of 6 December, according to a ZOE health study, prompting calls from some for restrictions to be reintroduced.
JN.1, a sub-lineage of Omicron, has been categorised by the UK Health Security Agency (UKHSA) because of its mutation and “increasing prevalence within the UK and international data”.
Head of primary care and public health at Imperial College London, Prof Azeem Majeed, said JN.1 “appears to be the fastest growing variant in the UK at the moment”.
