LONDON (Reuters) – People who have had COVID-19 are very unlikely to contract it again for at least six months after their first infection, according to a UK study of healthcare workers on the front lines of the fight the coronavirus pandemic.
The results should reassure the more than 51 million people around the world who have been infected with the pandemic disease, researchers at the University of Oxford said.
“This is really good news, because we can be sure that, at least in the short term, most people who contract COVID-19 will no longer get it,” said David Eyre, professor in the health department of the people of Nuffield in Oxford, who co-led the study.
Isolated cases of reinfection with COVID-19, the disease caused by the SARS-CoV-2 virus, had raised concerns that immunity would be short-lived and that recovered patients could quickly fall ill again.
But the results of this study, conducted in a cohort of British healthcare workers – who are among the people most at risk of contracting COVID-19 – suggest that cases of reinfection will likely remain extremely rare.
“Being infected with COVID-19 offers protection against re-infection for most people for at least six months,” Eyre said. “We did not find any new symptomatic infections in any of the participants who had tested positive for antibodies.”
The study, which is part of a large staff testing program, covered a 30-week period between April and November 2020. Its results have not been reviewed by other scientists, but were published before their release. review on MedRxiv website.
During the study, 89 of the 11,052 staff without antibodies developed a new infection with symptoms, while none of the 1,246 staff with antibodies developed a symptomatic infection.
Staff with antibodies were also less likely to test positive for COVID-19 without symptoms, the researchers said, with 76 without antibodies testing positive, compared to just three with antibodies. These three were all fine and did not develop symptoms of COVID-19, they added.
“We will continue to closely monitor this cohort of staff to see how long the protection lasts and if the previous infection affects the severity of the infection if people are infected again,” Eyre said.
Reporting by Kate Kelland, editing by Nick Macfie