Lifting the lockdown at the end of next month would be a disaster for the NHS, a top scientist has warned.
Professor John Edmunds, an epidemiologist who is part of government scientific advisory group Sage, cautioned against easing restrictions in February even if the target for COVID-19 vaccinations is met.
A national lockdown was implemented on 4 January but the Prime Minister has said he hopes some restrictions can be eased after the top four priority groups have received their first jabs in the middle of next month.
Prof Edmunds advised against this, telling BBC Radio 4’s Today programme: “I think it would be a disaster if we removed restrictions in, say, the end of February when we have gone through this first wave of the vaccination.”
Watch: COVID-19 vaccines update in numbers
Prof Edmunds added: “First of all, vaccines aren’t ever 100% protective, and so even those that have been vaccinated would be still at some risk.
“Secondly, it is only a small fraction of the population who would have been vaccinated and if you look at the hospitalisations at the moment, about half of them are in the under 70s, and they are not in the first wave to be vaccinated.
“If we relaxed our restrictions we would immediately put the NHS under enormous pressure again.”
There are twice as many COVID-19 hospital patients in two regions of England as there were at the peak of the first wave in April.
According to the government’s official coronavirus figures, there are currently 4,303 people in hospital with the virus in the east of England — up from 1,621 during the April 2020 peak.
In the South East, there are currently 5,487 COVID patients in hospitals, compared to an April peak of 2,347.
The UK’s coronavirus vaccine rollout has started well, with more than 3.2 million people receiving the first dose of a COVID-19 vaccine - around double the number compared to last week.
The government has a programme to vaccinate nearly 14 million of the most vulnerable people by mid-February and analysis from a Scottish vaccination plan which was accidentally posted online showed the country could have every UK adult vaccinated by mid-July.
According to the Our World in Data website, Britain has so far administered the fourth most vaccines per 100 people in the world.
Meanwhile, Prof Edmunds said it was “likely” two COVID-19 variants first identified in Brazil were already in the UK despite the government tightening travel rules this week.
The government banned flights from South America, Portugal and Cape Verde on Thursday in response to the emergence of the new variants, having previously banned travel from South Africa because of a new COVID-19 strain.
Aviation minister Robert Courts said on Saturday morning the government has a "very strong" package of measures in place to protect the public from any new coronavirus variants.
He told BBC Radio 4's Today programme they are "toughening up already tough requirements" to ensure that new variants do not arrive from abroad while the vaccine is rolled out.
He added a "total ban" on travel to the UK would not be right, and that pre-departure testing, passenger locator forms and the quarantine period make the system "robust".
Watch: What you can and can't do during England's third national lockdown