A third wave of coronavirus could cause up to 50,000 more deaths despite the rollout of vaccines, a scientist has warned.
Professor Jeremy Brown, a member of the government’s Joint Committee on Vaccination and Immunisation (JCVI), said there could be a “big third wave”.
His warning came as prime minister Boris Johnson said the easing of England’s lockdown restrictions will “inevitably” lead to more infections and deaths.
Prof Brown, an expert in respiratory infection at University College London Hospitals, said there could be tens of thousands more deaths.
"I feel mighty relieved that we are now in a position where a very high proportion of the vulnerable population have been vaccinated so, if control of the virus is lost, then the damage it can do will be relatively restricted," he told BBC Radio 4's Today programme on Tuesday.
"But when I say relatively restricted, what I mean is that a big third wave could still end up with 30,000 to 50,000 deaths, potentially, if it was a similar sort of size to the previous waves that we've had."
On Monday, England’s lockdown restrictions were eased, allowing pubs and restaurants to serve food and drink outside, while shops, gyms, beauty salons, hairdressers, libraries and zoos all reopened.
But Johnson warned on Tuesday: “As we unlock, the result will inevitably be that we will see more infection, sadly we will see more hospitalisation and deaths, and people have just got to understand that.”
He urged people to continue to “exercise restraint” as beer gardens were packed and shoppers flocked to high streets on Monday.
And Chris Hopson, chief executive of NHS Providers, said people should not assume the country is on a “one-way, inexorable, inevitable track to it all being fantastic”, despite the vaccine rollout.
“I know I might sound a bit like a prophet of doom the day after we’ve started enabling people to go back to the pub garden, but the reality is there are … really good reasons why we need to be cautious here,” he told Sky News.
“We need everyone to put their own personal pedal to the metal and ensure they follow the rules.”
On Tuesday, people in England aged 45 or over were invited to come forward to book their first Covid-19 jab, after the government met its target of offering a vaccine to all over-50s and those in high-risk categories.
The NHS booking website for the new age group temporarily crashed on Tuesday because of demand. There are an estimated 3.7 million people in England aged 45 to 49.
The NHS in England said 19 out of 20 of those most at risk of the virus have now received their first dose of a Covid-19 vaccine.
Shortly after the jab booking site was hit by technical issues, vaccines minister Nadhim Zahawi tweeted that the problem had been “fixed”.
Meanwhile, a 28-year-old solicitor become one of the first people in England to receive the Moderna jab on Tuesday, as the UK’s third coronavirus vaccine was rolled out.
Emily Sanderson received the vaccine at the Sheffield Arena vaccination centre.
Ms Sanderson, who has an underlying health condition, was due to receive the AstraZeneca vaccine, but this was changed to Moderna, the NHS said.
It comes after UK regulators said that people under the age of 30 should be offered an alternative to the AstraZeneca vaccine, saying there was a possible link between the jab and “extremely rare” blood clots.
This means people aged 18 to 29 who are offered the jab will be offered the Pfizer or Moderna jab until other vaccines are approved for use.
In Scotland, travel restrictions are to be eased from Friday and more people will be able to meet up outdoors, first minister Nicola Sturgeon said on Tuesday.
She said a reduction in prevalence of the virus meant some acceleration of planned lockdown easing was possible to support mental health and wellbeing.
From Friday, people in Scotland will be able to leave their local authority area for the purposes of socialising, recreation or exercise, though travel between the mainland and some islands will not be permitted.
Rules on gatherings will also be relaxed, with six adults from up to six households able to meet up outside.
Watch: Outdoor dining and drinking returns in England