arlier this month, in a wood-panelled room at a country estate in Massachusetts, three defiantly unmasked professors gathered around a large oak table to sign a declaration about the global response to the pandemic. One academic had flown across the Atlantic from Oxford; another had travelled from California. The signing ceremony had been carefully orchestrated for media attention, with a slick website and video produced to accompany the event, and an ostentatious champagne toast to follow. You may not have heard of the “Great Barrington declaration” but you’ll likely have seen the headlines that followed it. Journalists have written excitedly about an emerging rift in the scientific community as the consensus around the most effective response to Covid supposedly disintegrates. The declaration, which called for an immediate resumption of “life as normal” for everyone but the “vulnerable”, fuelled these notions by casting doubt on the utility of lockdown restrictions. “We know that all populations will eventually reach herd immunity”, it stated. Scientists were swift in their response. The declaration’s core assumption, that population immunity will be achieved by allowing life to go on as normal and shielding only the most vulnerable from the virus, is entirely speculative. The thrust of its argument is based on a false opposition between those who argue for lockdown and those who are against it, when in fact lockdowns are one of numerous measures that scientists have called for, and are seen as a short-term last resort to regain control. And shutting away the most vulnerable as life continues as normal is not only inhumane, but impossible: by this measure, the carers, household members and frequent close contacts of vulnerable people would also need to isolate. Moreover, young people with pre-existing conditions they don’t yet know about can be equally susceptible, and “long Covid”, with its debilitating host of symptoms, affects people of different ages. The truth is that a strategy of pursuing “herd immunity” is nothing more than a fringe view. There is no real scientific divide over this approach, because there is no science to justify its usage in the case of Covid-19. We know that when it comes to other coronaviruses, immunity is only temporary. The president of the UK’s Academy of Medical Sciences, in a detailed rebuttal, describes the declaration’s proposals as “unethical and simply not possible”. It’s time to stop asking the question “is this sound science?” We know it is not. Instead, we should be more curious about the political interests surrounding the declaration. Within hours of its launch, it had seeded political and ideological impact disproportionate with its scientific significance. The hashtag #signupstartliving began trending on social media. Its three signatories were later received by Alex Azar, the US secretary of health and human services, and by Scott Atlas, recently appointed as Donald Trump’s health adviser, who tweeted on 8 October that “top scientists all over the world are lining up with the @realDonaldTrump #Covid_19 policy”. And on a call convened by the White House, two senior officials in Trump’s administration cited the declaration. Was this ever really about science? When scientists disagree, we expect them to provide evidence for their position. Yet the declaration’s many contentious statements are unreferenced – and the manner of its launch seems designed to amplify publicity over substance. If anything, the tactics employed in this performance have serious implications for the public’s trust in scientists. It is already clear that the declaration is being used to legitimise a libertarian agenda. Indeed, some authors have questioned if it was ever anything about health, or whether its motivations were always purely economic; as the professor of political economy Richard Murphy put it, the declaration was “the economics of neoliberalism running riot … revealing in the process its utter indifference to the interests of anyone but those who can ‘add value’ within that system”. As we approach one of the most important elections in the history of western democracy (itself described as a referendum on lockdown), we should be asking who funded this piece of political theatre, and for what purpose. The American Institute for Economic Research (AIER), where the declaration was signed, is a libertarian thinktank that is, in its own words, committed to “pure freedom” and wishes to see the “role of government … sharply confined”. The institute has a history of funding controversial research – such as a study extolling the benefits of sweatshops supplying multinationals for those employed in them – while its statements on climate change largely downplay the threats of the environmental crisis. It is a partner in the Atlas network of thinktanks, which acts as an umbrella for free-market and libertarian institutions, whose funders have included tobacco firms, ExxonMobil and the Koch brothers. Our questions to the AIER about its relationship to the three signatories went unanswered, but it has posted a number of articles about the declaration and herd immunity on its website. These are not the names one would associate with sound public health policies. But the trio of scientists who fronted the declaration were able to put the weight of the world’s most prestigious academic institutions behind their statements – Stanford, Harvard and Oxford – giving the declaration a sheen of respectability. The views of these scientists about lockdown and the pursuit of herd immunity are no doubt sincerely held (though, notably, not published in any peer-reviewed scientific articles), but they are falling into a trap set by the right. Rightwing free-market foundations and institutions have long attempted to savage the public reputation of well-intentioned policies such as those aimed at curbing ecological threats and limiting smoking. Some of the tactics these organisations have used in the past are those we see at play in the Great Barrington declaration: discredit the scientific consensus, spread confusion about what the right response is and sow the seeds of doubt. It seems that lockdown restrictions aimed at bringing the virus under control are merely the latest target in this rightwing stealth campaign. The science is clear: attaining herd immunity to coronavirus via uncontrolled infection is a fringe view, peddled by a minority with no evidence to back up their position. What’s less certain is the political and economic interests that lie behind this declaration. Let the debate begin on those. Trish Greenhalgh is a professor of primary care health sciences at Oxford University. Martin McKee is professor of European public health at the London School of Hygiene & Tropical Medicine. Michelle Kelly-Irving is a social epidemiologist working for the French institute of health research – Inserm – based at the Université Toulouse III, France