The UK has recorded the highest daily total of lab-confirmed coronavirus cases since the pandemic began, as the Omicron variant spreads.
Official figures show there had been 78,610 new cases recorded as of 9am on Wednesday.
It is the highest figure announced since mass testing began in summer last year.
Prime Minister Boris Johnson is set to hold a press conference from Downing Street later on Wednesday.
Late last week the UK Health Security Agency (UKHSA) warned the UK could see one million Omicron cases by the end of December and the new Covid-19 variant could become the dominant strain of the virus in the country within days.
At a briefing on Friday, the UKHSA said analysis of 581 people with confirmed Omicron cases showed the Oxford/AstraZeneca and Pfizer/BioNTech vaccines provided “much lower” levels of protection against Omicron when compared with the Delta variant which is currently the dominant strain in the UK.
However, scientists did say the early data showed vaccine effectiveness “considerably increased” soon after a booster dose, raising protection to around 70-75 per cent.
Dr Mary Ramsay, head of immunisation at the UKHSA, said: “These early estimates should be treated with caution but they indicate that a few months after the second jab, there is a greater risk of catching the Omicron variant compared to Delta strain.
“The data suggest this risk is significantly reduced following a booster vaccine, so I urge everyone to take up their booster when eligible.
“We expect the vaccines to show higher protection against the serious complications of Covid-19, so if you haven’t yet had your first two doses please book an appointment straight away.”
Sage scientists have warned the NHS could be overwhelmed by the variant if we fail to get a grip on it.
Professor Graham Medley, from the London School of Hygiene & Tropical Medicine and a member of the Scientific Advisory Group for Emergencies (Sage), told BBC Radio 4’s Today programme he is worried “we could see numbers of people being admitted to hospital getting very large” if infections continue to rise and spill into older age groups.
It came as Dr Jenny Harries, chief executive of the UK Health Security Agency, told MPs the Omicron coronavirus variant is “probably the most significant threat we’ve had since the start of the pandemic” and warned of a “staggering” number of cases in the next few days compared with what has gone before.
She said the “real potential risk” is whether “cases turn into severe disease, hospitalisations and deaths”, but added that it is “too early” to be clear on that.
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