Unlocking too quickly would lead to a substantial surge in Covid infections, the UK’s chief medical adviser says.
Prof Chris Whitty said that would be dangerous and risk lives among the many vulnerable people not yet protected by the vaccine.
He told MPs on the science and technology committee that another rise in cases was inevitable at some point.
“A lot of people may think this is all over. It is very easy to forget how quickly things can turn bad.”
Prof Whitty added: “All the modelling suggests there is going to be a further surge, and that will find the people who either have not been vaccinated, or where the vaccine has not worked, and some of them will end up in hospital and sadly, some of them will go on to die,”
His comments come amid pressure from backbench Tory MPs to relax restrictions more quickly, given how far infection rates have fallen.
However Prof Whitty said that, despite the encouraging progress on getting infection rates down, the step-by-step roadmap in England – which will not see all restrictions lifted until June at the earliest – was needed so the government could monitor the impact of each change.
It takes around three weeks for immunity to build up following the first dose of the vaccine, which means only the first four priority groups – the over 70s, health and care staff and the extremely clinical vulnerable – will have developed protection.
While most Covid deaths have been in these groups, nearly half of hospital admissions have been seen in the under 70s.
In addition, he said it took three to four weeks after a restriction was lifted for government advisers to be able to properly assess the impact which, with the one week’s notice the government wants to give for any changes to the roadmap, that meant a five week gap was needed.
“If you look at the steps, each one is quite a big one. You want to be absolutely confident it is safe.”
He also said people who think the UK is not at risk anymore should look at what is happening in continental Europe, with countries seeing rates going up and having to re-introduce restrictions.
‘We should not expect zero deaths in long-term’
Longer term, Prof Whitty said it was unrealistic to expect there to be zero deaths. Modelling has suggested even with a gradual lifting of restrictions there could be 30,000 deaths by the summer of 2020.
He said this was because, while the vaccines were good, they were not 100% effective – and as some people would refuse to be vaccination there would be people who remain unprotected and the virus would “find them”.
Predicting exactly how many would die was not possible said Prof Whitty. He added it would be a “significant number”, albeit nothing like what we have seen over the past year.
But he said this was the case for flu, pointing out in a “bad flu season” 20,000 people could die.
And while there was an expectation Covid would become seasonal, with future surges seen in the autumn and winter, although cases in the summer could not be ruled out.