COVID-19 immunity lasts at least five months for people who have been infected by the virus and provides about 83 percent protection against reinfection, compared to those who haven't had the virus, according to a preliminary study conducted by scientists at Public Health England, an executive agency of the U.K.'s health department.
Among 6,614 study participants who had COVID-19 antibodies, researchers identified 44 potential reinfections — an 83 percent protection rate, according to the study. The immunity appeared to last for at least five months. This indicates that anyone who contracted COVID-19 during earlier stages of the pandemic may now be more susceptible to reinfection, researchers said. However, some people with immunity who carry high levels of the virus in their nose and throats still remain infectious, according to preliminary findings from the next stage of the study.
The findings are based on data collected between June and November.
"We now know that most of those who have had the virus, and developed antibodies, are protected from reinfection, but this is not total and we do not yet know how long protection lasts. Crucially, we believe people may still be able to pass the virus on," said Dr. Susan Hopkins, lead study author and senior medical advisor at Public Health England.
The study has not yet been peer-reviewed and the findings are part of ongoing research that will assess how long immunity may last, the effectiveness of vaccines, as well as details into what proportion of people with immunity may still be infectious.