The UK’s chief scientific adviser said it is hoped the Government’s approach to tackling coronavirus will create a “herd immunity” to the disease.
Sir Patrick Vallance said some of the social distancing measures put in place by the Government, including self-isolating for seven days if symptoms develop, are “actually quite extreme”.
His comments come after former health secretary Jeremy Hunt questioned the Government’s decision not to cancel large gatherings after Prime Minister Boris Johnson warned many more families would “lose loved ones before their time”.
Sir Patrick told the BBC that the advice the Government is following is not looking to “suppress” the disease entirely but to help create a “herd immunity in the UK” while protecting the most vulnerable from it.
Asked if there is a fear that clamping down too hard on its spread could see it return, Sir Patrick said: “That is exactly the risk you would expect from previous epidemics.
“If you suppress something very, very hard, when you release those measures it bounces back and it bounces back at the wrong time.
“Our aim is to try and reduce the peak, broaden the peak, not suppress it completely; also, because the vast majority of people get a mild illness, to build up some kind of herd immunity so more people are immune to this disease and we reduce the transmission, at the same time we protect those who are most vulnerable to it.
“Those are the key things we need to do.”
Mr Hunt, chair of the House of Commons Health select committee, was asked on BBC Newsnight what he thought about the decision not to cancel large gatherings, and he said: “I think it is surprising and concerning that we’re not doing any of it at all when we have just four weeks before we get to the stage that Italy is at.
“You would have thought that every single thing we do in that four weeks would be designed to slow the spread of people catching the virus.”
Mr Hunt said the UK is in a “national emergency” and that many people “will be surprised and concerned” that the UK is not moving sooner.
He said other countries that have taken tougher action appear to have been successful in turning back the tide of the virus.
It comes as France became one of the latest European countries to close all schools, universities and nurseries, while in the US, all major sport has been suspended and Broadway performances have been stopped for a month.
On Thursday, Ireland announced the closure of all schools and childcare facilities and other public spaces such as museums, while Scotland banned gatherings of more than 500 people.
The UK Government said it would not move to close schools yet as the evidence for its effectiveness is lacking, though this will be kept under review.
Sir Patrick said school closures now would see educational establishments shut down for “many months”.
He told LBC: “Because of the nature of this disease and the way it spreads and its duration, we would have to close schools for many months, not just a few weeks.
“Schools would need to be shut for a very prolonged period.
“Children, of course, aren’t going to separate for long periods, they are going to go and do other things together.
“And they may go and stay with grandma, one of those in the most vulnerable group.”
Mr Johnson has said the latest Government approach is aimed at protecting the elderly and those most vulnerable to the disease, but said precautions would mean severe disruption across the country “for many months”.
Between 5,000 and 10,000 people in the UK are thought to be infected with Covid-19 already.
Mr Johnson told reporters at a press conference on Thursday: “We’ve all got to be clear: this is the worst public health crisis for a generation.
“It is going to spread further and I must level with you, I must level with the British public: many more families are going to lose loved ones before their time.”
He said that people with even mild coronavirus symptoms, including a continuous cough or high temperature, must stay at home for at least seven days.
School trips abroad should be stopped, people over 70 with serious medical conditions are being told not to go on cruises, and officials warned the advice is likely to develop so that entire households could be told to self-isolate.
Sir Patrick said it is “eye-catching” to order the cancellation of mass gatherings and sporting events but that the chances of contracting the disease by attending such occasions are slim.
He told the BBC: “Mass gatherings do have some impact, it is not that they don’t do anything if you stop them.
“But they are very much more minor than the other ones.
“The most likely place you are going to get an infection from is a family member, a friend, someone very close in a small space, not in the big space.”
High-profile people to be diagnosed with Covid-19 include Arsenal head coach Mikel Arteta and BT boss Philip Jansen.
Chelsea’s full squad has also gone into self-isolation after winger Callum Hudson-Odoi tested positive for coronavirus.
Sophie Gregoire Trudeau, wife of Canadian prime minister Justin Trudeau, has tested positive for Covid-19 and the couple are in isolation.
Mr Trudeau’s office said he is feeling well and will continue to work.
A spokesman for the Cabinet minister told the PA news agency that International Development Secretary Anne-Marie Trevelyan has tested negative for coronavirus.
She was tested on Thursday and will now remain at home.
England’s chief medical officer, Professor Chris Whitty, said the peak of the outbreak is most likely still 10 to 14 weeks away.
He said it is feared people will become “fatigued” by more stringent measures if they are brought in too soon and therefore they would lose their maximum effect.
The number of people who have tested positive for the virus in the UK rose to 596 while the death toll in British hospitals is 10, while the FTSE 100 closed down by more than 10% on Thursday as fears over Covid-19 sparked the index’s worst bloodbath since 1987, while markets fell in Asia on Friday.