Three Scots-based academics are among 39 key people behind a call for a return to 'life as normal' using herd immunity.

The call comes in what is called the Great Barrington declaration which says that the least vulnerable to the effects of coronavirus should be permitted to "resume life as normal"

The was originally authored by Sunetra Gupta of Oxford University, Jay Bhattacharya of Stanford University, and Martin Kulldorff of Harvard University and originally co-signed by 36 other public health scientists and medical practitioners before being launched.

Among the 36 are Dr Gabriela Gomes, a professor of mathematics and statistics at the University of Strathclyde, who has said there is no longer a rationale for lockdown restrictions as the UK is "achieving herd immunity".

Also co-signing were disease modeller Dr Paul McKeigue and biostatistician Dr Simon Wood both from the University of Edinburgh.

The 'anti lockdown petition' as it has been called, has gone on to be supported by at least 108,333 members of the public, 4,245 scientists and 7,692 medical practitioners so far.

The declaration calls for a herd immunity approach to tackling coronavirus, in which the old and vulnerable are shielded from the virus while allowing those less susceptible to resume ordinary life.

READ MORE: UK's herd immunity strategy over coronavirus called into question

It suggests that the physical and mental health aspects of restrictive coronavirus policies are of "grave concern." Instead, the declaration recommends an approach to the virus called 'Focused Protection'.

The declaration lists some of the effects of restrictions on short and long-term public health as, "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."

It adds that "keeping students out of school is a grave injustice," while "keeping these measures in place until a vaccine is available will cause irreparable damage, with the underprivileged disproportionately harmed."

Dr Gomes said: "Since the beginning of the pandemic we have been acquiring immunity in the population and I've been developing mathematical models to describe that.

HeraldScotland:

"According to our models we are achieving herd immunity right now, which means that an epidemic growing out of control is no longer an expectation.

"So, given that, if we expect the numbers of infections to continue roughly constant for some time and then decline as more immunity is acquired, the rationale for constraining society and lockdowns...is no longer met."

The University of Strathclyde professor told LBC that the UK would achieve herd immunity when 20% of its population became immune to Covid-19.

The Declaration argues that the harms of Covid-19 to the young are less than some other harms, including flu, and that building herd immunity could reduce the risks for everyone "As immunity builds in the population, the risk of infection to all - including the vulnerable - falls," the declaration continues.

"We know that all populations will eventually reach herd immunity - ie 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 suggests that "those who are not vulnerable should immediately be allowed to resume life as normal, while those who are vulnerable or ill remain at home."

The idea of herd immunity has proved controversial among a number of experts. The Great Barrington declaration comes a few weeks after Sir Simon Stevens, leader of the NHS in England, remarked that asking everyone over 65 to shield would amount to "age-based apartheid."

Others have pointed out that the approach ignores growing evidence of the after-effects of "long Covid", where lasting symptoms have debilitated sufferers for months after contracting the virus.

It is also unknown whether herd immunity would actually work as an approach to stem the tide of infections, as immunity may not last for very long.

Professor Jeremy Rossman, for instance, suggested that antibody responses to coronavirus may "decay rapidly", pointing out that there have also been cases of re-infection.

Sweden is an example of a country where herd immunity has been attempted, but statistics show that the country had high mortality rates among the vulnerable - suggesting the same might occur if the method was tried elsewhere.

Professor James Naismith, director of both 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."

He added that the declaration omits some "critical scientific information."