Covid masks could return amid a warning latest Covid wave could be the "biggest yet".
The JN.1 variant, an offshoot of the Omicron strain, now accounts for 65 per cent of all cases.
According to the latest data from COG-UK that number is up 4 per cent from early November.
Experts predict cases could continue to rise throughout January following socialising over the festive period.
Face masks could be coming back
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Virus expert at Imperial College London Professor Peter Openshaw told The Sun: "We're going to see quite a major surge in infections over the coming weeks - the wave could be bigger than anything we've seen before."
"To help stop the spread, those who haven't had the Covid booster should consider wearing face masks in public places, like on trains, when shopping and at large events."
According to the World Health Organisation (WHO), wearing a mask reduces the spread of bugs by reducing the number of infectious particles that may be inhaled or exhaled.
Between December 3 and 9, 5,975 people had a confirmed positive test result. This shows an increase of 38.6 per cent compared to the previous seven days.
Between December 3 and 9, 5,975 people had a confirmed positive test result
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Virologist from the University of Nottingham Professor Jonathan Bell said the rise in JN.1 cases is a "sign of things to come" however downplayed the risks.
He said: "New variants will continue to evolve, replace pre-existing variants causing major outbreaks of infection.
"I don't think this [particular] rise is too concerning.
"We know that in the majority of people vaccines continue to protect against serious disease, that's why it's important for vulnerable people to ensure that they've had their latest vaccine booster jab."
By the end of December 13, 3,854,999 people had been given a spring booster.
Although JN.1 is believed to be more infectious than the other Covid sub-variants circulating in the UK at the moment, there is nothing to suggest it causes more severe disease.
However, emerging anecdotal evidence suggests the new bug could be making people more unwell due to waning immunity.
Prof Openshaw added: "It's a surprisingly devious virus, sometimes making people quite ill and occasionally leading to having 'long Covid'."