The coronavirus mutation known as Stealth Covid is now the most dominant variant in the UK, according to health experts.
The variant, a subtype of Omicron, is now responsible for 52% of cases of Covid across the country according to the UK Health Security Agency.
The variant, also known as BA.2, has been found to be the dominant strain in the latest figures up to February 20.
It has been dubbed Stealth because it is difficult to detect as a variant in a PCR test - unlike its parent Covid variant Omicron. At the start of February Stealth accounted for just 19% of cases.
According to the UKHSA Stealth many be more transmissable (infectious) 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.
