Britain reported record Covid-19 prevalence for the last week of 2021 on Wednesday, with one in 15 people in England infected.
The increasing number of cases has put huge strains on public services such as hospitals, which face staff shortages and growing admissions.
British Prime Minister Boris Johnson has resisted imposing stringent lockdown measures in England. Instead, he has bet that a vaccine booster drive and caution among the population will be enough to constrain the latest wave of infections, despite the arrival of the highly transmissible Omicron variant.
More than 220,000 Covid-19 cases were recorded on one day in the last week, and the provision of services and testing capacity is increasingly under strain.
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In England, the estimated Covid-19 prevalence was one in 15 for the week ending Dec. 31 -- over 6% of the population and up from an estimate of one in 25 for the previous week, the Office for National Statistics said.
ONS figures also showed record prevalence in Scotland, Wales and Northern Ireland. In all, an estimated nearly 3.75 million people were infected across the United Kingdom.
{{/usCountry}}ONS figures also showed record prevalence in Scotland, Wales and Northern Ireland. In all, an estimated nearly 3.75 million people were infected across the United Kingdom.
{{/usCountry}}The Omicron variant has had the biggest impact in London, where one in 10 people tested positive.
Johnson said on Tuesday that England had a chance to "ride out" the surge in Covid-19 infections without shutting down the economy, thanks to vaccinations and evidence that Omicron is milder than previous variants.
Despite this, he warned of substantial disruption from staff absences as people self-isolate. He will update parliament later on Wednesday on his Covid-19 strategy.
The UK Health Security Agency said on Wednesday that people without Covid-19 symptoms who test positive on a rapid lateral flow test in England will not need to confirm the result with a PCR test that needs to go to the lab for processing, a move designed to ease pressure on the testing system.