Downing Street made clear that such a policy, advocated by a group of academics, scientists and medics, could lead to young people infecting older generations who are at greater risk of being killed by coronavirus.
No10 said the idea, being promoted under the banner of the Great Barrington Declaration, was based on an “unproven assumption” that it was possible to stop the virus being passed between generations to more vulnerable people.
The Prime Minister’s official spokesman said: “We have considered the full range of scientific opinion throughout the course of this pandemic and will continue to do so.”
However, he also stressed: “It’s not possible to rely on an unproven assumption that it’s possible for people who are at lower risk, should they they contract the virus, to avoid subsequently transmitting it to those who are at a higher risk and who would therefore subsequently face a greater chance of ending up in hospital or worse in an intensive care unit.”
He added that the Government’s Chief Medical Officer Professor Chris Whitty had also made clear that the strategy adopted to combat Covid took into account the impact of restrictions on people’s physical and mental health, as well as additional non-Covid deaths linked to the measures such as individuals not swiftly accessing cancer care.
However, a group of British and other experts are arguing that people who are less vulnerable to the effects of Covid-19 should be allowed to return to normal life.
The Great Barrington Declaration, which is earning thousands of signatures from medical professionals, academics and the general public, calls for a herd immunity approach to tackling the Covid-19 pandemic while protecting the most vulnerable populations.
Academics from the universities of Oxford, Nottingham, Edinburgh, Exeter, Cambridge, Sussex, York, St George’s University of London, Strathclyde, Leicester, Queen Mary University of London and the University of East Anglia are among experts from around the world who have signed the document.
The declaration states: “As infectious disease epidemiologists and public health scientists we have grave concerns about the damaging physical and mental health impacts of the prevailing Covid-19 policies, and recommend an approach we call Focused Protection.
“Current lockdown policies are producing devastating effects on short and long-term public health. The results (to name a few) include lower childhood vaccination rates, worsening cardiovascular disease outcomes, fewer cancer screenings and deteriorating mental health - leading to greater excess mortality in years to come, with the working class and younger members of society carrying the heaviest burden. Keeping students out of school is a grave injustice.
“Keeping these measures in place until a vaccine is available will cause irreparable damage, with the underprivileged disproportionately harmed.
“We know that vulnerability to death from Covid-19 is more than a thousand-fold higher in the old and infirm than the young. Indeed, for children, Covid-19 is less dangerous than many other harms, including influenza.
“As immunity builds in the population, the risk of infection to all - including the vulnerable - falls. We know that all populations will eventually reach herd immunity - i.e. the point at which the rate of new infections is stable - and that this can be assisted by (but is not dependent upon) a vaccine. Our goal should therefore be to minimise mortality and social harm until we reach herd immunity.
“The most compassionate approach that balances the risks and benefits of reaching herd immunity, is to allow those who are at minimal risk of death to live their lives normally to build up immunity to the virus through natural infection, while better protecting those who are at highest risk. We call this Focused Protection.”
It adds: “Those who are not vulnerable should immediately be allowed to resume life as normal. Simple hygiene measures, such as hand washing and staying home when sick should be practised by everyone to reduce the herd immunity threshold. Schools and universities should be open for in-person teaching. Extracurricular activities, such as sports, should be resumed. Young low-risk adults should work normally, rather than from home. Restaurants and other businesses should open.
“Arts, music, sport and other cultural activities should resume. People who are more at risk may participate if they wish, while society as a whole enjoys the protection conferred upon the vulnerable by those who have built up herd immunity.”
Commenting on the declaration, Prof Rossman, honorary senior lecturer in virology at the University of Kent, said: “Unfortunately, this declaration ignores three critical aspects that could result in significant impacts to health and lives.
“First, we still do not know if herd immunity is possible to achieve. Herd immunity relies on lasting immunological protection from coronavirus re-infection; however, we have heard many recent cases of re-infection occurring and some research suggests protective antibody responses may decay rapidly.
“Second, the declaration focuses only on the risk of death from Covid-19 but ignores the growing awareness of long Covid, that many healthy young adults with mild infections are experiencing protracted symptoms and long-term disability.
“Third, countries that have forgone lockdown restrictions in favour of personal responsibility and focused protection of the elderly, such as Sweden, were not able to successfully protect the vulnerable population.”
Prof James Naismith, director of the Rosalind Franklin Institute, and of the University of Oxford, said: “The main signatories include many accomplished scientists and I read it with interest. I will not be signing it however.
“The declaration risks the same error we have seen with the UK’s track trace and isolate scheme - one can promise a scheme that is very easy to describe but is hard to deliver.”
NHS in England boss Sir Simon Stevens has said that asking all over-65s to shield to slow the transmission of the second wave of coronavirus would be “age-based apartheid”.