More than a third of the world’s population has been urged to stay at home. Stock markets have collapsed and authorities have thrown vast sums of money at the global economy to stop it from plunging into depression. Yet the most chilling aspect of the coronavirus crisis gripping governments worldwide is uncertainty.
The world is being brought to a standstill by Covid-19, a disease caused by a virus that the best scientific minds have known about for less than four months. Their advice cannot be definitive. As Mark Rutte, the Dutch prime minister, has put it, in a crisis like this, leaders have to make 100 per cent of the decisions with 50 per cent of the data. Among their most important decisions is how and when the lockdowns will end, when drug treatments are still unproven and a safe, effective vaccine could be 12-18 months away. One measure will be critical: systematic, rapid and widespread testing.
We cannot easily free people from their homes until we know whether doing so will unleash a new wave of infection. But it will be difficult to ascertain this without vastly more testing than most countries have done so far.
Even a rich G7 country such as the UK has been struggling to carry out 10,000 tests a day, a target that a rising band of critics point out it has been aiming at for at least three weeks. These antigen tests detect the presence of the virus itself, by checking a nose or throat swab in a laboratory. They are vital for tracking the course of infection and staying one step ahead of it. They also let frontline health workers and other essential staff know if it is safe to go to work. But they will not be enough alone to restart economies.
Who will feel safe working beside someone who is virus-free one week and contagious the next, especially when scientists think more than 30 per cent of cases can be asymptomatic. One answer lies in a new type of test, on blood, that researchers are rushing to develop. It can detect whether people have already been infected and therefore have some immunity to the virus. Experts say that such an antibody test should be cheaper and easier than the first and could potentially be done at home.
But hurdles remain. This is a newer type of test, unlike the antigen one, and its reliability must first be guaranteed. Assuming that happens soon, it is still unclear how long immunity to the new virus lasts and how strong it will prove to be.
Finally, there are significant logistical considerations. Tests would have to be carefully collected and the data collated centrally so authorities knew what portion of the population had been infected. So-called “herd immunity” occurs once a certain percentage of a population is immune to an infection, so knowing that percentage is pivotal to working it out.
In addition, there are sensitive questions about certifying people who have antibodies to the virus, a move that could create a world in which “immunity certificates” are needed to get a job or board a plane.
The reality is that we will probably need both types of tests before normal economic life can be restored, along with a standing army of laboratories, supplies and trained staff that can be activated when needed. South Korea and other countries that invested in mass screening after the wake-up calls of past viral outbreaks offer lessons in what can be done.
Following South Korea’s lead will take time and cost money. But the sums will be negligible compared to those of continued lockdowns or even milder forms of social distancing. Countries must do whatever it takes to test, now.