In a relief to healthcare workers who put their lives under risk while treating those with Covid-19, new findings from a study of thousands of healthcare workers in England show that those who got Covid-19 and produced antibodies against the virus are highly unlikely to become infected again.
Researchers led by David Eyre, University of Oxford, England, looked to more than 12,000 healthcare workers at Oxford University Hospitals from April to November 2020.
During the beginning of the study, 11,052 of them tested negative for antibodies against SARS-CoV-2, suggesting they hadn’t had Covid-19. But the other 1,246 tested positive for antibodies, evidence that they’d already been infected.
As soon as the initial testing over, all participants received antibody tests once every two months and diagnostic tests for an active Covid-19 infection at least every other week. What the researchers discovered was rather interesting.
Eighty-nine of the 11,052 healthcare workers who tested negative at the outset later got a symptomatic Covid-19 infection. Another 76 individuals who originally tested negative for antibodies tested positive for Covid-19, despite having no symptoms.
Posted as a pre-print on medRxiv, the findings suggest that acquired immunity from an initial Covid-19 infection offers protection against reinfection for six months or maybe longer.
Questions remain about whether the acquired immunity is due to the observed antibodies alone or their interplay with other immune cells. It will be important to continue to follow these healthcare workers even longer, to learn just how long their immune protection might last.
(With inputs from The OnLook News Research Bureau)