Russell, who is a photographer specialising in theatre, has not worked since he fell ill. He is precise about the date: 14 March. “I’ve had plenty of time to look back and think, what was I doing then? And how I wished I hadn’t been doing that.”

His illness lasted two weeks and he felt better not long afterwards, then experienced terrifying chest pains “like someone was sitting on me”. But hospital doctors and his GP said tests showed there were no problems – a common experience of long-Covid patients, according to Frances Simpson, a founder of the support group Long Covid SOS, who says many struggle to have their symptoms taken seriously by the medical profession.

Russell was luckier than most – he changed GP, and the new doctor ordered an antibody test which confirmed he had had the virus. He is now one of 500 patients taking part in the Coverscan clinical trial into the impact of Covid-19.

“When people refuse to wear masks or to even obey the most basic of social distance rules, it’s very, very frustrating,” Russell said. “I just want to shake them and say ‘I’ve been living with this for six months’.