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Rival scientists divided over lockdowns may make a good story – but how accurate is it?

<span>Photograph: Andrew Milligan/PA</span>
Photograph: Andrew Milligan/PA

The cardinal rule of coronavirus policy is that you must follow “the science”. Or, at the very least, you must say that you are. After the US’s disastrous response to the pandemic, Donald Trump still insists he is “guided by science”. In the UK, Boris Johnson and his ministers always claimed that our own bumbling response was either “led by the science” or “following the science”, even as Britain’s infection rate soared above other countries that were also, in their own words, following the science.

Sometimes it is easy for us to separate out false claims about science from real ones. Early in the crisis, the majority of mainstream scientists, and institutions such as the World Health Organization, supported swift lockdown measures. Trump resisted this approach, instead putting his faith in quack cures that his closest scientific advisers clearly opposed. Johnson has tended to drag his heels, taking the right scientific advice too late, as with lockdown, or making a mess of the execution, as with testing and tracing. Their departures from the sanctified path of science are obvious.

The real trouble occurs when the science itself appears fractured. As we enter a new period of lockdown measures, the British Medical Journal has reported that scientists are divided into “two camps” over how severe restrictions should be. A recent open letter to the government headed by several prominent scientists argued against imposing a general lockdown – which most scientists agree is the best response to a virulent second wave – and instead for measures to be “targeted” at vulnerable populations, letting the rest of us go about our lives as normal.

The letter was widely covered, and two of its signees, Carl Heneghan, head of the Centre for Evidence-Based Medicine at Oxford University, and Sunetra Gupta, a professor of epidemiology, also at Oxford, were invited to meet Johnson and his advisers at a Sage committee meeting to discuss lockdown policy. It appears Johnson now has two versions of the science from which to choose.

The signees don’t break any new scientific ground. Instead, they voice many of the same criticisms levied at lockdown since the beginning of the crisis: that we may be overestimating the threat posed by Covid-19; that the total cost of locking down the economy and medical services may be deadlier than the virus itself; and that the public might be better served by limiting lockdown to vulnerable and elderly people who are most at risk from Covid-19.

The letter gathers these criticisms under a new scientific imprimatur. By effectively saying “not all scientists”, Heneghan in particular seems to be spoiling for a fight with the establishment. Writing in the Mail on Sunday a few days before the letter was published, he said that Johnson’s team was a “Dad’s Army”, with “little experience of the job at hand”, and that the government’s “mediocre” scientific advisers were making the wrong decisions based on models produced by “agents of doom”.

How should we evaluate this apparent split? First, we should be clear that the positions in the letter represent those of a small minority of scientists. The overwhelming scientific consensus still lies with a general lockdown. A less-covered letter that was published the same week, from some 40 other prominent scientists, noted that Covid-19 had caused deaths and long-term illness across many age groups, and that separating out vulnerable individuals in a population of millions was “practically impossible”.

But our media has a tendency to amplify minority positions, particularly if they appear to confirm the right-libertarian worldview that runs through many newspapers. The narrative of the maverick scientist bucking conventional wisdom (and confirming the wisdom of many columnists) seems too good for some papers to pass up. Scientific consensus doesn’t sit well with an industry built upon conflict. Indeed, the anti-lockdown statements of both Heneghan and Gupta have received extensive media coverage.

The signatories of the anti-lockdown letter also make a worrying departure, not just in how they interpret science, but in their entire approach to scientific advice. Throwing caution aside, they rely upon very specific readings of coronavirus data that is still extremely messy.

Both Gupta and Heneghan have criticised the scientific approach to Covid-19 before. Gupta has published studies suggesting that a far higher proportion of the population may have immunity to Covid-19 than most estimates suggest, and that we may be near the fabled point of “herd immunity”, while Heneghan has long criticised estimates of the outbreak’s severity. In August he successfully caused the government to revise its death toll down by more than 5,000 people when he criticised Public Health England’s counting methods. Lately, Heneghan has been arguing there is no “second spike” and that case numbers are rising because the government’s test sensitivity is set too high – allowing tiny amounts of dead or inactive virus to be counted as a live case.

Neither argument is scientifically invalid. But they are both scientifically incomplete. Gupta’s studies are not yet peer-reviewed and are based on observations, not experimentation. Although Heneghan’s critique of testing methods may merit further study, rising hospital admissions may soon prove the spike is real, whatever the test results say. In both cases, these theories seem to have bloomed into a general belief that the entire consensus around coronavirus is too cautious.

But caution has always been the point. We are used to scientific advice that is based upon years of peer review and replication. Science on a short timescale is messy and fallible, as this crisis has shown. Basic questions about the transmissibility and effects of the virus are still unresolved months after the outbreak began. The rule, when translating uncertainty into policy recommendations, has been to manage risk. We don’t know how catastrophic a truly uncontrolled outbreak would be, and so scientific advice tends to avoid steering us into that unknown.

The drama of an apparent scientific split has already played out once before. During the beginning of the pandemic, John Ioannidis, a well-respected researcher at Stanford University, was vocally opposed to lockdown. His theory, based on early observational data, was that Covid-19 mortality was much lower than the scientific consensus assumed. In the scientific world, Ioannidis was treated critically, but seriously. Studies trying to determine the true rate of infection to mortality are ongoing. But in the press, Ioannidis was cited in countless columns, penned articles of his own, and called lockdown a “a once-in-a-century evidence fiasco”. His prediction, in April, that the US would have “fewer than 40,000 deaths” turned out to be a gross underestimate.

Critiques in good faith are part of the scientific process. But a compliant media spun Ioannidis’s theorising into a policy argument long before it was ready to stand up to scrutiny. If there were two camps, his was a hastily constructed lean-to. The scientists behind this new letter may find their ideas fare better in the long term, but it should take extraordinary new evidence about the virus or its detection and treatment to change course now. They haven’t provided that.

  • Stephen Buranyi is a writer specialising in science and the environment