Life has returned to normal for millions in Britain since coronavirus restrictions were lifted over the summer.
But while the rules have vanished, the virus hasn't.
Many scientists are now calling on the government to reimpose social restrictions and speed up booster vaccinations as coronavirus infection rates, already Europe's highest, rise further.
Covid deaths and infections surging
The number of Covid-19 deaths in Britain has risen to their highest daily level since early March.
The UK Statistics Authority reported on Tuesday 223 people had died within 28 days of testing positive for Covid, bringing the total death toll to 138,852.
This was the highest number of Covid deaths in Britain since March 9, when 231 people died.
On Monday, almost 50,000 new coronavirus cases were reported, with the seven-day incidence at 435 per 100,000 residents. More than 43,700 were reported on Tuesday.
Last week, the Office for National Statistics estimated that one in 60 people in England had the virus, one of the highest levels seen in Britain during the pandemic.
Masks could be reintroduced as immunity wanes
In July, Prime Minister Boris Johnson's government lifted all the legal restrictions that had been imposed more than a year earlier to slow the spread of the virus, including face coverings indoors and social distancing rules.
Some modellers feared a big spike in cases after the opening up. That didn't occur, but infections remained high, and recently have begun to increase - especially among children, who largely remain unvaccinated.
Some scientists say a bigger factor is waning immunity — millions of people have been vaccinated for more than six months, and studies have suggested vaccines' protection gradually wanes over time.
Last month, the prime minister said the country might need to move to a "Plan B" — reintroducing measures such as mandatory masks and bringing in vaccine passes — if cases rose so high in the fall and winter that the health system came under "unsustainable" strain.
For now, the government says it won't change course, but will try to boost vaccination rates, with a new ad campaign and an increased number of sites outside schools where kids can receive their shots.
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