AS NEW WAVES of covid-19 sweep the world, lockdowns are back in fashion. This time, though, they are a harder sell. They certainly save lives. But it is now clear that the lost jobs, the disruption to education and medical services, and the harm to mental health that they cause all exact tolls of their own—and these are paid not just in misery, but in deaths. Systems of “test and trace”, intended to stop those exposed to the virus from passing it on, seem to have worked in some places, but not in others.
In the absence of a vaccine, or of effective drug treatments, the question of how much longer this can go on for is thus being asked more insistently. And on October 4th a trio of public-health experts from Harvard, Oxford and Stanford universities put out a petition calling on governments to change course in a radical way.
The Great Barrington Declaration, named after the town in Massachusetts where it was signed, proposes that the contagion be allowed to spread freely among younger and healthier people while measures are taken to protect the most vulnerable from infection. This approach rests on the concept of “herd immunity”, whereby the disease would stop spreading when a sufficient share of the population had become immune as a result of infection.