The novel coronavirus is tearing through the United Kingdom's population of older residents once again, due to the highly transmissible BA.2 sub-variant of the Omicron strain.

But scientists analyzing the latest UK trends in the virus and the COVID-19 disease it causes said they are, at least, hopeful the latest wave of infections has peaked among the young.

Imperial College's React study, which has tracked the virus since May 2020, recorded more new infections during March than during any previous month.

"We are reassured that (the rates) in younger groups seem to be coming down; they can't go up forever," the BBC quoted Paul Elliott, director of the React project, as saying.

But Elliott said infections among young people only began to plateau toward the end of the month.

The expert, who leads the epidemiology department at Imperial College London, said he was worried about the spread of the virus among people aged 55 and older.

The study, which extrapolated the levels of infection from tests on a random group of 109,000 people, concluded 6.37 percent of England's population had the virus during March, a sharp increase on the 2.88 percent who were positive during February.

By March 31, a staggering 8.31 percent of people aged 55 and older had the virus, which made it 20 times more prevalent then than its average level of prevalence since May 2020.

The unprecedented rise in infections since February followed England ending all legal restrictions on how people should interact, the requirement to wear face masks, and the need to self-isolate following a positive test result.

Elliott said his team had recorded an increase in social mixing since the restrictions ended.

But he said waning immunity offered by vaccines administered more than six months earlier had also contributed to the sharp rise in infections.

The survey reported that the "high and increasing prevalence in older adults may increase hospitalizations and deaths, despite high levels of vaccination".

The UK infection levels in March were more than 40 percent higher than they were during the previous high, which came during January, the Financial Times newspaper noted.

And scientists are monitoring yet another new strain of the virus-Omicron XE-which the UK Health Security Agency said had infected 637 people in England as of March 22.

The World Health Organization said the XE strain could be 10 percent more transmissible than the BA.2 strain, which itself was 30 percent more transmissible than the original Omicron variant.

Ironically, the React survey will not be able to follow the XE variant's progress because the UK government has stopped its funding.

As of April 1, London has also stopped funding free test kits, leading critics to complain that, going forward, no one will know who has the virus and who has not.