COVID infections are at their highest ever recorded levels according to new research, which has been tracking cases since May 2020.
The findings from the REACT-1 study show the increase is driven by high rates among school-aged children, with 1 in 17 children infected between 19 October and 29 October.
Researchers warn the next ten days will be “critical” as children return to the classroom.
Across England, the overall prevalence of the virus was 1.72% compared with 0.83% in September.
The regional breakdown of the data shows an increase in infections in all areas, apart from Yorkshire and the Humber, with prevalence highest at 2.18% in the South West.
Scientists say one “viable hypothesis” for the cluster of cases in this region could be related to mistakes at a private laboratory in Wolverhampton, which wrongly told thousands of people from the South West their tests were negative.
The React study uses random swab tests to calculate levels of COVID in the general population.
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The study suggests infections had started to fall at the end of October, which is probably due to the half-term holiday.
A similar trend was seen this time last year, although cases started to rise once the break ended.
Director of the React programme, Professor Paul Elliott, from Imperial College London said: “We do know that we saw a very, very similar pattern … at the same time last year, where over the half-term period the rates dropped and then actually they rebounded and went up again.
“So I think watching what happens in the next week, ten days, is going to be really critical.”
Researchers believe as we spend more time indoors during winter there is an increased possibility of infection.
But they also say the vaccination of school children and the adult booster programme could reduce transmission.
Elsewhere, another piece of research says the introduction of COVID-19 vaccine passports can “reduce cases and deaths”.
Writing in the British Medical Journal, academics from the Tony Blair Institute for Global Change said vaccine passports can provide “reassurances” and limit spread in a crowded or enclosed environment.