The antibodies were present “regardless of the severity of the illness, the age of the patients or the presence of other pathologies,” according to a statement from the San Raffaele hospital in Milan. The researchers, working with Italy’s ISS national health institute, studied 162 patients with symptomatic coronavirus who turned up at the emergency room during the country’s first wave of infections last year.

Blood samples were taken in March and April and again at the end of November from those who survived. Some 29 patients died. “The presence of neutralising antibodies, while reducing over time, was very persistent – eight months after diagnosis, there were only three patients who no longer showed positivity to the test,” said the statement, issued jointly with the ISS.