he arms race between human immunity and viral pathogens is constant. The contest had been hidden from the public until swine flu, the first global influenza pandemic for more than 40 years, hit the UK in 2009. This outbreak was contained with fewer than 500 deaths. Britain was lulled into a false sense of security that its infection control measures would be enough to contain a new infectious disease. Governments pursued a course of mitigation, where it is accepted a deadly disease will spread but the losses are bearable. This was true of Labour and Conservative governments. Alan Johnson, health secretary in Gordon Brown’s administration, admitted to a peers’ inquiry in 2009 that at the “peak of a ‘reasonable worst-care scenario’ pandemic, intensive care capacity may well be inadequate”. That this calculation had not changed since is the reason for the extreme lockdown we are enduring. What has altered is the nature of the threat. Covid-19 is 50 times more deadly than swine flu. It is far more easily transmitted. The world is more globalised, heightening the risk of rapid spread of the virus, especially one that travels with close contact. These were all quantifiable risks. It is disastrous that such a virus has been left to spread untracked around the country. This would have tested any health system, let alone one running close to full capacity and groaning under a winter flu season. Our shortcomings are now being painfully exposed. The global demand for the ventilators that help severely ill coronavirus patients to breathe looks almost certain to outstrip supply. Plans for homemade machines are being drawn up on the fly. Frontline medics complain they are putting their lives at risk because of a lack of protective equipment. The failure to act fast enough lies behind the testing fiasco. Testing is central to reducing the fatality rate, because it leads to early detection. It allows transmission to be curbed and for resources to be pointed rapidly to the infected. But to test requires staff, equipment and chemicals. The worry is that the NHS does not have enough trained workers to operate the tests. Then there are concerns over supply. Lombardy in Italy, one of hardest-hit places in Europe, is home to one of the largest makers of testing swabs. There is a worldwide race to secure the chemical reagents required for the kits. Michael Gove acknowledged on Tuesday evening that Britain has much ground to make up in order to copy South Korea’s successful rollback strategy. Yet Seoul’s achievement was founded on mass-sourcing reagents in January when they were plentiful. Now it’s much tougher, as Jean-François Delfraissy, the immunologist who heads France’s Covid-19 response, warned this month. He said France had “a huge problem with the reagents used in the tests. These basic reagents are from China and the United States. The production of machines stopped in China and the US keeps the [reagents] for itself.” What is required is more international cooperation to prevent these rivalries from causing avoidable deaths. China has a crucial role to play, having experienced five respiratory virus epidemics in 20 years. The success of Germany’s well-resourced public health system in handling the outbreak ought to be a model to emulate. David Alexander, professor of risk at University College London, told the New Statesman that pandemic preparation involves “telling governments what they don’t want to know, to spend money they don’t have, on something they don’t think will happen”. Every year, 600,000 people die in the UK. If unchallenged, Covid-19 threatens to almost double that and overwhelm the NHS. In the face of uncertainty, it’s appropriate for government to be resilient to extreme events. The science may not be black and white, and no one can possess perfect actuarial clarity. But this crisis has shown us how we can – and must – insure against the uncertainty.