Story at a glance
- Researchers behind the SIREN study performed regular antibody and PCR testing on more than 20,000 health care workers across the United Kingdom between June and November.
- The study found that antibodies provided an 83 percent rate of protection against coronavirus reinfection for those previously infected, compared to people who have never contracted the virus.
- Scientists, however, found those with immunity may still be able to carry the virus in their nose and throat and could spread it to others.
A new study suggests people who have been infected with COVID-19 may have some form of immunity against the coronavirus for at least five months on average, but may still spread the virus.
The study led by Public Health England (PHE) — which has yet to be peer reviewed — found that antibodies provide an 83 percent rate of protection against coronavirus reinfection, compared to people who have never contracted the virus.
The preliminary findings published Thursday show the protection lasts for at least five months from the time the patient first became sick.
Researchers behind the SIREN study, which stands for SARS-CoV-2 Immunity and Reinfection Evaluation, performed regular antibody and PCR testing on more than 20,000 health care workers across the United Kingdom between June and November.
Scientists detected 44 potential reinfections out of 6,614 participants who tested positive for antibodies.
Researchers, however, found those with immunity may still be able to carry the virus in their nose and throat and could spread it to others, emphasizing the need for people to continue practicing public health recommendations to slow the spread, such as wearing masks, washing hands and social distancing.
“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,” Susan Hopkins, senior medical adviser at PHE and co-author of the study, said.
“This means even if you believe you already had the disease and are protected, you can be reassured it is highly unlikely you will develop severe infections but there is still a risk that you could acquire an infection and transmit to others. Now more than ever it is vital we all stay at home to protect our health service and save lives,” Hopkins said.
The research was done prior to the widespread dissemination of the new variant in the U.K. that public health officials say is more contagious. Scientists are working to understand whether antibodies provide protection against the variant.
The study’s authors said they are continuing to monitor health care workers for 12 months to see how long any immunity may last, the effectiveness of vaccines and to what extent people with immunity carry and transmit the virus.
Research published in the journal Science earlier this month showed immunity to SARS-CoV-2 could last eight months or more.
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