The coronavirus mutation known as Stealth Covid is now the dominant variant in the UK, according to health experts.
The variant, which is a subtype of Omicron, is now responsible for 52% of cases of Covid across the country according to the UK Health Security Agency.
Known as BA.2, it has been found to be the dominant strain in the latest figures up to Sunday, February 20.
It has been dubbed Stealth Covid because it is difficult to detect as a variant in a PCR test - unlike its parent variant Omicron.
At the start of February Stealth accounted for just 19% of cases.
According to the UKHSA Stealth many be more transmissible than original Omicron and Japanese research found it could cause a worse illness in animals who had no immunity.
There are also concerns it could be better at evading human immunity and vaccines.
But there is no evidence it is causing more serious disease in the human population.
In the UK 91.5% of the population aged over 12 have had one vaccination, 85.2% have had two and 66.4% have had either a third dose or a booster does, according to the latest government data.
In the last seven days 234,103 people tested positive for covid in the UK, down 24% on the previous seven days.
Yesterday the Mirror reported that tourists going abroad may no longer have to fill in complicated travel forms when they return to the UK after their Easter holidays.
Covid documents that travellers must complete before entering Britain seem set to be ditched after the Health Secretary Sajid Javid backed the move.
Government sources told the Mirror it is now “fairly likely” the change will be in place before families jet off for the Easter holidays.
A formal process would still have to take place, with ministers signing off the scrapping of the passenger locator form at a Covid meeting in the coming weeks.
Transport Secretary Grant Shapps is understood to have been pushing for the move to help the travel industry get back on its feet.
