IT has been darkly amusing hearing epidemiologists, clinicians and statisticians trying to avoid estimating the acceptable mortality rate from the next Covid wave: 5,000, 10,000, 20,000?

How many deaths is too many? “Not our job,” they say. “It's a political decision ... every death is a tragedy ... can't put a number on it”. Perhaps, but the Government has to.

Sajid Javid, the new Health Secretary, admits that cases could reach 50,000 or even 100,000 a day. Even with vaccination, we can expect more than 50 deaths a day from that, according to Professor Neil Ferguson of Imperial College. Come autumn/winter we could easily have “bodies piling high in their thousands” as the PM is alleged to have remarked before the last lockdown.

Could any government survive if another wave caused up to 20,000 deaths from Covid? That is the astonishing gamble Boris Johnson is taking by lifting restrictions at the very moment when cases are rising rapidly. Nicola Sturgeon has been careful to distance herself from Mr Johnson's Freedom Day, sensing another opportunity to accuse him of putting the economy before lives. (And conveniently diverting attention from Scotland becoming the Covid hotspot of Europe.)

Read more: Cummings has got Johnson off the Covid hook

But look at it another way. Deaths from flu can vary between 5,000 and 20,000 each winter, and we seem to be able to cope with that. You may be wondering why this is. If every death is a tragedy, how can we tolerate avoidable mortality on such a scale every year? Why don't we wear masks every winter, since they're as effective against influenza as Covid? Maybe we will.

To repeat: just how many deaths is acceptable? I can't answer that, and neither can any of the scientists who have been dodging the question over the last 48 hours. There is a benchmark, but the bench keeps shifting, with social awareness. It isn't entirely rational.

What epidemiologists will say is that the situation has changed radically with the vaccination programme. Ninety-nine per cent of deaths from Covid thus far have been in the over-40s and that cohort is now nearly all vaccinated. On the other hand, seven million people, according to the NHS, have failed to come forward to seek treatment from other serious diseases like heart, cancer, mental health issues. It is almost certain that the number of non-Covid excess deaths will exceed Covid this winter– but since that is still a hidden epidemic it doesn’t figure.

In addition to the non-Covid death toll, there is the damage to the economy, large parts of which have ceased to function, especially in hospitality and leisure. The human cost of this is concealed right now because the Chancellor has been papering over the wreckage with vast quantities of printed money, which will soon run out. The economy has to get back to work as furlough ends and deficit reduction begins.

The Herald: The Scottish Government has cleverly exploited what might be called the “Boris Gap” in the timetable for normalityThe Scottish Government has cleverly exploited what might be called the “Boris Gap” in the timetable for normality

But again, what level of mortality is acceptable in order to keep the economy functioning? This has been a heated debate since the first lockdown. Trade unionists rightly say that we can't put profits ahead of people's lives. Why should train and bus drivers be expected to place themselves in harm's way? But this callous calculus is with always with us.

Why do we allow cars to pollute the atmosphere that is breathed by bus drivers? More to the point, why do we allow wood-burning stoves which, according to DEFRA, cause an astonishing 38% of cancer-causing particulate matter in our air, three times that of traffic? The British Heart Foundation says that 11,000 heart deaths a year are caused by particulate poisoning.

Strip away the veil of ignorance and we discover that, as a society, we tolerate avoidable death on an epic scale.

Covid will be with us in one variant or another for years, decades even. Sir Patrick Vallance, the UK Chief Scientific Adviser says “there is zero chance of zero Covid”. So I can understand why Mr Johnson is saying it’s time to “learn to live with Covid” open up, return to normal. However, normal isn't what it used to be, and returning to it may well destroy Mr Johnson politically.

Take masks. There is little evidence that removing face coverings now will greatly affect the Covid death rate – the lifting of mask mandates in American states has not led to spikes. However that's not what most people believe, and the BMA has said we shouldn't take the risk. Labour and the Scottish Government have already clocked the opportunity to revive #BorisTheButcher on Twitter.

Read more: No more talk of eliminating coronavirus as Sturgeon imposes lockdown lite

Yesterday, Kate Forbes, the Scottish Finance Secretary announced that, come August 8, Scotland will go “beyond level zero” and lift restrictions on socialising, public events and weddings. But she added “base line measures like face masks and home working will continue”. In other words, some things that might actually spread the virus, like large gatherings, will be allowed, while some things that might not will be retained.

Masks are a political gift at a time when Covid is running rampant. There is no more visible token of social concern than wearing masks “to protect others” – even if they don’t very much. The Scottish Government will insist on Scots continuing to don face coverings, preferably in tartan, because it will be a visible sign that Scotland cares more than England.

Throughout the pandemic, the Scottish Government has cleverly exploited what might be called the “Boris Gap” in the timetable for normality. Nicola Sturgeon always leaves a few weeks in which she can claim that the PM is risking people's lives before lifting restrictions in an almost identical manner to those south of the Border.

This serves to obscure the inconvenient reality that Scotland, which this time last year Ms Sturgeon said was on course for “elimination”, now curiously has the highest Covid hot spots in Europe. Zero Covid was the grandest illusion of the pandemic. Only by making society impossible could coronavirus conceivably be eradicated.

In the end, the Prime Minister is right, even though he'll probably u-turn on masks. We have to live with this disease because we can't live, normally, without it.

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