Can you catch coronavirus twice?

Recently there were scare stories about being able to get re-infected with Covid, but the reports didn’t give the true picture.

I feel we need some clarification. Here’s the story from Jane Parry in the BMJ.

A 33-year-old man from Hong Kong first acquired Covid in March, having very mild symptoms but testing positive. Ivan Fan-ngai Hung, research team member and clinical professor in the University of Hong Kong’s department of medicine said: “He remained in hospital for three weeks until he tested negative twice.”

Four and a half months later, after a week’s trip to Spain, the man was asymptomatic but again tested positive when he returned to Hong Kong and had quite a high viral load.

Researchers found the two episodes were caused by different strains of Covid-19. Professor Hung, however, insisted that people who’d had a previous infection should still be considered for vaccination.

Paul Hunter, professor in medicine at the University of East Anglia, has said, “The evidence should not be too surprising. It is, however, important that this is documented.

“Commentators have been saying for some time that immunity is unlikely to be permanent and may only last a few months.

“Given the different intensity of the antibody response in people with mild or severe illness and the subsequent decay in levels, it is likely that those with a mild illness will have a shorter duration of immunity than those with severe illness.”

Brendan Wren, professor of microbial pathogenesis at the London School of Hygiene and Tropical Medicine, said, “This is a very rare example of reinfection, and it should not negate the global drive to develop vaccines.”