LONDON (Reuters) - Britain will most likely only have reliable data on the spread of the new Omicron coronavirus variant in early January and possibly in the week between Christmas and New Year, a leading health official said on Thursday.
Susan Hopkins, the chief medical adviser at the UK Health Security Agency, said so far there were 15 proven cases of Omicron in hospitals, but that the number was likely to be much higher.
"I think the earliest that we will have reliable data is the week between Christmas and New Year and probably early January," she told a parliamentary committee.
Hopkins said experts would need about 250 individuals in hospital to make a severity assessment compared with the earlier Delta variant.
"We start running that assessment when we start having enough cases who have been admitted hospital to do it and then we run it daily," she said.
Chris Whitty, England's chief medical officer, also told the committee that the numbers of hospitalisations could rise rapidly and could see more people being admitted to hospital on a single day than during the previous peak in January.
"You could end up with a higher number than that going into hospital on a single day," he said. "The whole point about this is it going to be really concentrated in a very short period of time."
(Reporting by Kylie MacLellan, writing by Elizabeth Piper. Editing by Andrew MacAskill)