Stealth virus 33% easier to transmit

UK cases of Stealth Omicron have doubled in a couple of days as a study found the subvariant is 33% more transmissible than its original.

The subvariant BA.2 is spreading fast, with 4,294 cases identified by last Friday.

The UK genomic database recorded 1,993 cases just two days earlier.

Previous estimates had expected a slower doubling rate of five to six days.

It has been dubbed Stealth Omicron because it cannot be flagged up by standard PCR tests.

A study in Denmark, which is the epicentre for the subvariant, suggests that it could soon take over from BA.1.

Analysis of cases in 8,500 households found that people infected with BA.2 were a third more likely to infect others when compared to those who had BA.1.

Frederik Plesner, of Copenhagen University, said: “If you’ve been exposed to BA.2, you have 39% probability of being infected within seven days. With BA.1 it is 29%.”

Worldwide, BA.1 accounts for more than 98% of Omicron cases but BA.2 quickly became dominant in Denmark.

On Monday, Health Secretary Sajid Javid said: “Our world-class health surveillance operations are keeping a close watch on BA.2. There is currently no evidence that it is any more severe.”

Denmark has become one of the first European Union countries to scrap most pandemic restrictions.