THE aim of suppressing coronavirus is "increasingly unfeasible" and likely to be doing more harm than good, according to experts who are calling on the government to reconsider blanket measures.

In a letter to the Prime Minister, chief medical officers, and the UK's chief scientific adviser, leading academics including Scottish bacteriologist Professor Hugh Pennington, argue that current policy "is inconsistent with the known risk-profile of Covid-19 and should be reconsidered".

It comes as Boris Johnson prepares to made a statement to the House of Commons ahead of curfews which will force pubs and restaurants across England to close at 10pm.

First Minister Nicola Sturgeon is also set to outline a package of measures for Scotland in a bid to curb a rising number of Covid infections.

READ MORE: Five graphs which explain the key Covid statistics in Scotland right now

However, in their letter dated September 21 - co-written by Professor Carl Heneghan, director of the centre for evidence-based medicine at Oxford university; Professor Sunetra Gupta, professor of theoretical epidemiology at Oxford University; Professor Karol Sikora, a consultant oncologist and professor of medicine at Buckingham University; and Sam Williams, director and co-founder of Economic Insight - the experts insist that the objective of suppressing the virus is "increasingly unfeasible and is leading to significant harm across all age groups, which likely offset any benefits".

The 28 signatories include Prof Pennington, emeritus professor of bacteriology at Aberdeen University; Professor Nick Colegrave, chair of experimental evolution at Edinburgh University; Professor Simon Wood, professor of statistical computing at Edinburgh University; as well as miciobiologists, geriatric and intensive care medics, oncologists, economists, statisticians, epidemiologists, and experts in infectious disease.

They call on policymakers to pursue "more targeted measures" adding: "We are mindful that the current circumstances are challenging, and that all policy decisions are difficult ones.

"Moreover, many people have sadly lost loved ones to Covid-19 throughout the UK.

"Nonetheless, the current debate appears unhelpfully polarised around views that Covid is extremely deadly to all (and that large-scale policy interventions are effective); and on the other hand, those who believe Covid poses no risk at all."

They go on to say that placing "all weight on reducing deaths from Covid fails to consider the complex trade-offs that occur", both within the healthcare system itself and "between healthcare, society and the economy".

They add that they are "concerned about the sole reliance on 'case numbers' and 'the R' to inform national and local policies, as these metrics are subject to significant measurement and interpretation challenges (and further, neither is an outcome that matters to society)".

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The letter notes that 89% of Covid mortality has occurred in the over-65s and is concentrated in those with pre-existing medical conditions.

"This large variation in risk by age and health status suggests that the harm caused by uniform policies (that apply to all persons) will outweigh the risks," write the professors.

In particular, they point to a decrease in urgent cancer referrals which, according to projections by scientists writing in the journal Lancet Oncology in August, could culminate in up to 1200 extra lives from cancer over the next 10 years.

They also point to Office for Budget Responsibility (OBR) forecasts that unemployment in the UK will reach 11.9% by the end of the year.

They conclude by urging leaders to target policies to protecting those most at risk, while providing the public with information on the "actual risk they face from Covid-19 by health and age status".

They write: "Our strategy should therefore target interventions to those most at risk. For example, Germany's case fatality rate among patients over 70 is the same as most European countries.

"However, its effective reduction in deaths is based around a successful strategy of limiting infections among those older than 70."

Germany (with a population of 83 million) has recorded around 9,500 known Covid deaths, compared to 41,800 in the UK, with a population of less than 67 million.

The case fatality rate (CFR) is the proportion of Covid deaths out of the total number of people diagnosed with the disease.

They add: "Finally, behavioural interventions that seek to increase the personal threat perception of Covid should be reconsidered, as they likely contribute to adverse physical and mental health impacts beyond Covid.

"Consideration should also be given to whether policies that are intended to 'reassure', may in fact reinforce a heightened perception of risk."

The letter comes after England's chief medical officer warned that the UK was on course for 50,000 Covid cases a day by mid-October and 200 deaths a day by mid-November.

READ MORE: Leaked memo suggests pubs and restaurants could be closed in October 

Professor Chris Whitty said the country faced a "difficult balance" between reducing the number of people dying directly from Covid, preventing the NHS from being overwhelmed by Covid patients which would in turn hamper diagnoses and treatments for other conditions, and the knock-on harms of lockdown on the economy.

"If we do too little, this virus will go out of control and we will get significant numbers of direct and indirect deaths," said Prif Whitty.

"But if we go too far the other way then we can cause damage to the economy which feeds through to unemployment, to poverty and to deprivation - all of which have long-term health effects."

He stressed that there was "no evidence" that the virus was any milder than it had been in Spring, and that it was "clearly more virulent" than seasonal influenza - which claims 7000 lives in the UK in a normal year and more than 20,000 in a bad year.

To date in Scotland, according to National Records of Scotland data, there have been 4,236 Covid deaths.

Prof Whitty insisted that it could not be left to individuals to choose their own risk of exposure.

He said: "A lot of people say 'well, can't people just be allowed to take their own risk?'

"The problem with a pandemic or an epidemic infection like this is that if I, as an individual, increase my risk I increase the risk to everyone around me and then everyone who is a contact of theirs.

"Sooner or later the chain will meet people who are vulnerable or elderly or have a long-term problem from Covid.

"So you cannot in an epidemic just take your own risk - unfortunately you're taking risk on behalf of everyone else."

He added that the most effective means of containing the virus were handwashing, wearing masks in enclosed spaces, physical distancing, self-isolating if you have symptoms, swift contact tracing, and reducing social interaction.