Two years on, what’s the evidence for lockdown?

Did lockdowns save lives? We will never have a definitive answer to this vital question because it was impossible to conduct controlled experiments — we don’t have two identical countries, one where lockdown was imposed and one where it wasn’t. Nor is it easy to compare similar countries, for the simple reason that every country in the world — bar Comoros in the Indian Ocean — reacted to Covid by introducing at least one non-pharmaceutical intervention (NPI) by the end of March 2020.

A team from Johns Hopkins University has, however, assessed the many (albeit flawed) studies into whether lockdown works — a ‘meta-analysis’. It reviewed 24 studies which attempted to compare countries according to the stringency of their lockdowns, on whether or not they introduced stay-at-home orders, and which looked at individual NPIs — which is possible because some countries, for example, introduced mask mandates and others did not.