England's Chief Medical Officer Professor Chris Whitty said it was “not realistic” to think there will be a stage where “there is not coronavirus circulating”.
He told a Downing Street press conference that the coronavirus vaccine would initially help to reduce Covid-19 deaths but social distancing and other measures would need to stay in place.
He said letting go of measures could lead to a “huge surge” in infections, particularly among people who are “a bit below the highest risk groups”.
“Some of those would get very seriously ill and end up in hospital and some of those would die. So we will need to keep it on beyond that period,” he added.
He said: “There will be more deaths probably for the foreseeable future but at a much lower level just as every year there are flu deaths – on an average year maybe 7,000 flu deaths, in a high year up to 20,000 flu deaths.
“This happens with infections, unfortunately, particularly in the elderly.”
Prof Whitty added: “We will not get to the point there is zero risk. And a decision for society, led by political leaders, is going to be at what level of risk do we actually start to raise these measures and that’s going to be a difficult choice. But we’re not anywhere near that yet.”
He said “population immunity” from Covid-19 would occur “if we have vaccines which actually can reduce transmission between people”.
He said there was a “high degree of confidence” that the approved Pfizer vaccine reduces the risk of severe disease, while data suggests that the in-development AstraZeneca-Oxford and Moderna vaccines also reduce such risk.
Prof Whitty added: “But we don’t yet know if this leads to a reduction in transmission. It’s likely to, to some degree, maybe not a complete reduction.
“And if it doesn’t do that then we will never achieve this concept of population immunity or herd immunity and then what we need is the vaccines to be at the highest possible rate because only people who are vaccinated will be protected.
“What we hope that actually what we’ll have is a vaccine that both protects the person who has them, very important for that, but also we hope will also protect people around them, it reduces transmission, but we’ll have to wait to see whether that’s possible over time.”
