Recovered Covid patients could be reinfected within a year: Amsterdam researchers

One year after a coronavirus infection, and maybe even earlier, a person can become infected with the same virus again, Amsterdam UMC researchers concluded based on research into the four known and harmless seasonal coronaviruses. This probably also applies to the novel coronavirus SARS-CoV-2, the researchers conclude.

The researchers looked at blood samples from a group of healthy people, who had blood drawn every three to six months since the 1980s, checking for antibodies against the seasonal coronaviruses. In this way they could track back when a corona infection and re-infection with the same virus happened. They found that the duration of immunity was "alarmingly short", with reinfection regularly occurring after one year, and in some cases more quickly. This applies to all four seasonal coronaviruses.

"Precisely because the viruses differ greatly and we found the same result for all viruses, we think that this is a common property of all coronaviruses," researcher Arthur Edridge said. "This means that the immunity is also short-lived for the new coronavirus SARS-CoV-2."

"So even though you had an infection with the new coronavirus this spring, it remains important to adhere to the RIVM guidelines. You could just get infected again," lead researcher Lia van der Hoek added."

SARS-CoV-2 has only been circulating in the world population for a short time, and reinfections have already been confirmed in the Netherlands, Hong Kong and Belgium. But exactly how long it takes on average before someone is susceptible to the virus again, was unknown until know.