In mid-March Paul Garner developed what he thought was a “bit of a cough”. A professor of infectious diseases, Garner was discussing the new coronavirus with David Nabarro, the UK’s special envoy on the pandemic. At the end of the Zoom call, Nabarro advised Garner to go home immediately and to self-isolate. Garner did. He felt no more than a “little bit off”.

Days later, he found himself fighting a raging infection. It’s one he likens to being “abused by somebody” or clubbed over the head with a cricket bat. “The symptoms were…