The largest and longest analysis to date of post-Covid recovery also warns that some patients’ antibody levels fell sharply, raising concern that while waiting for a return to full health, they could be reinfected with the coronavirus.

Almost two-thirds of the patients said they were still suffering from fatigue and muscle weakness, the researchers wrote in The Lancet. A little over a quarter had difficulty sleeping, and a little under a quarter experienced anxiety and depression. Overall, more women than men reported lingering symptoms, and people whose disease was more severe had poorer lung health. Their median age was 57.