An official UK study published on Thursday shows that a past Covid-19 infection provides some immunity for at least five months, but people can still be carriers and carriers of the coronavirus.
A Public Health England (PHE) analysis found that immunity acquired naturally from past infections provides 83% protection against re-infection compared to people who did not have the disease before.
This lasts at least five months from the first illness. However, experts have warned that immunocompromised people can still carry the virus in their nose and throat and therefore run the risk of passing it on to others.
“This study gave us the clearest picture to date of the nature of antibodies protection against Covid-19, but it is important that people do not misunderstand these early findings,” said Professor Susan Hopkins, senior medical advisor to the Public Health Department of England, who led the SIREN PHE study. …
“We now know that most of those who have contracted the virus and developed antibodies are protected from reinfection, but that is not all, and we do not yet know how long the protection lasts. We believe that people can still pass the virus turned on, ”she said.
She stressed that the results mean that even if you think you already have the disease and are protected, you can be confident that you are very unlikely to develop a severe infection, but there is still a risk that you could become infected and transmit to others.
“It is more important than ever that we all stay at home to protect our health and save lives,” she added.
PHE says it has regularly tested tens of thousands of healthcare workers across the UK for new Covid-19 infections since June, as well as antibodies that suggest people have been infected before.
While the SARS-CoV-2 Immunity and Reinfection EvaluatioN (SIREN) study will continue to assess whether protection can last longer, its results warn that people who contracted the disease in the first wave may now be vulnerable to reinfection.
Between June 18 and November 24, scientists identified 44 potential re-infections (two “probable” and 42 “possible” re-infections) of 6,614 participants who tested positive for antibodies. This represents 83 percent of the protection against re-infection.
PHE also warned that while those with antibodies have some protection against Covid-19 infection, the first data from the next phase of the study suggests that some of these people carry high levels of the virus and may continue to transmit the virus to others. … …
“Therefore, it is imperative that everyone continues to abide by the rules and stay at home, even if they previously had Covid-19, to prevent the virus from spreading to others. Remember to wash your hands regularly, wear face masks and make room for others to reduce the likelihood of transmission of the virus, ”the experts say.
The analysis was conducted prior to widespread adoption of the new highly transmissive variant VOC202012 / 01, and PHE said further work is underway in the laboratory to understand whether and to what extent antibodies provide protection against this variant.
The study will continue to monitor participants for 12 months to find out how long any immunity can last, the effectiveness of vaccines, and to what extent people with immunity are able to carry and transmit the virus.
The experts stressed that this first report does not contain evidence of antibodies or other immune responses from Covid-19 vaccines, and no conclusions should be drawn about their effectiveness.