MORE than half of the Omicron cases in England are among Brits who are double vaccinated, health officials have revealed.
The UK Health Security Agency (UKHSA) warned the mutant variant is “transmitting rapidly and successfully” after first being identified here last weekend.
It come as Omicron cases have more than trebled, with 92 detected in the past 24 hours bringing the total number in the UK to 134.
The UKHSA placed its highest “red alert” on the super strain amid fears it can dodge immunity from both vaccines and previous infections and spreads fast.
The agency found 12 of 22 Omicron cases in England were among people who had had at least two vaccine doses.
Two other people had had one jab at least four weeks before testing positive, six were unvaccinated and vaccine data on the other two cases wasn’t available.
None of the cases is known to have been hospitalised or died.
But the UKHSA said most cases were recent and pointed to a lag between onset of infection and hospitalisation and death.
Last night, it was confirmed there had been another 75 cases reported in England, taking the total figure to 104.
The first Omicron case was reported in Wales, with 16 more cases detected in Scotland, taking the total north of the border to 29.
First Minister Nicola Sturgeon has blamed a Steps concert in Glasgow on November 22 for one cluster of cases.
In its risk assessment, the UKHSA warned the variant has “mutations suggestive of reduced protection from vaccine derived immunity”.
It also warned of reduced protection from natural immunity among those previously infected with other variants such as Delta or Alpha.
🔵 Read our Omicron variant live blog for the latest news
But it cautioned that its confidence level in the findings is “low” as scientists wait for new data.
It comes as the Covid modelling squad SPI-M said it could be another five years before the virus stops being a danger to the NHS.
It means annual jabs could be here for the foreseeable future.
Yesterday, Covid cases in the UK topped 50,000 for the second day in a row – the first consecutive days with 50,000 cases for five months.
Dr Jenny Harries, chief executive of the UKHSA, said: “Thanks to very high levels of vaccine coverage we already have a robust wall of defence against Covid-19 as new variants emerge.
“We are working as fast as possible to gather more evidence about any impact the new variant may have on severity of disease or vaccine effectiveness.
“Until we have this evidence, we must exercise the highest level of caution in drawing conclusions about any significant risks to people’s health.”
Prof Rosemary Boyton, of Imperial College London, said: “The existing vaccines do appear to protect from hospitalisation and death, and there’s no reason for us to think that’s not going to be the case for any subsequent variant.”
Scientists here estimate that one in every 300 new cases are caused by the mutant super-strain, which was first reported from South Africa lat month.