Patients arrive in ambulances at the Royal London Hospital in London, England on January 5, 2021. The British Prime Minister made a national televised address on Monday evening, announcing that England would take action against the Covid-19 pandemic for the third time. This week, the UK recorded more than 50,000 new confirmed Covid cases for the seventh straight day.
Dan Kitwood | Getty Images News | Getty Images
LONDON – People infected with Covid-19 are likely to have some form of immunity for at least five months, according to initial results from a large new study in the UK
Preliminary results from Public Health England’s SIREN study, which surveyed thousands of UK healthcare workers to determine whether a previous infection would protect against future infections, found that antibodies had an 83% protection rate against those who were not infected re-infection present the disease.
This naturally acquired immunity appears to last at least five months, the report said. Reinfections in people with antibodies were rare, the study published Thursday found. Experts identified 44 potential reinfections among 6,614 participants who participated in the study.
However, initial findings also suggest that small numbers of people with antibodies may still be able to carry and transmit the virus, underscoring the need to comply with current coronavirus restrictions, Public Health England said.
The study has not yet been peer-reviewed or published in a medical journal. The authors emphasize that the results are an interim analysis of the data collected between June and November 2020.
Professor Susan Hopkins, a senior medical advisor at Public Health England and director of the SIREN study, said the research has “given us the clearest picture yet of the nature of antibody protection against Covid-19, but it’s important that people don’t get this early misunderstand.” Results.”
“We now know that most of those who had the virus and developed antibodies are protected from re-infection, but this is not complete and we don’t yet know how long the protection will last. The bottom line is that people may still be in are able to pass the virus on. “
“Even if you think you have already had the disease and are protected, you can be sure that you are very unlikely to develop serious infections, but you are still at risk of getting the infection and passing it on to others . Now, more than ever, it is important that we all stay home to protect our health care and save lives, “she added.
The study comes from the launch of coronavirus vaccines developed by Pfizer-BioNTech, Moderna and Oxford University, and AstraZeneca in the UK. The former two vaccine candidates were found to be around 95% effective at preventing Covid-19 infection and the latter, on average, 70% effective.
As with naturally acquired immunity, scientists are still unsure of how long protection from coronavirus vaccines could last. They are also not sure whether a vaccinated person can still transmit the virus.
The leaders of the SIREN study stressed that this preliminary report “does not provide any indication of the antibody or other immune responses of Covid-19 vaccines, nor should any conclusions be drawn about their effectiveness,” adding that vaccine reactions will occur later this year be taken into account.
The study continues to look at whether protection might last longer, with PHE indicating that the results mean that people who contracted the disease in the first wave may now be at risk to get it again.
The SIREN (SARS-CoV-2 Immunity & Reinfection EvaluatioN) study has conducted regular antibody and PCR testing on 20,787 health care workers (including frontline clinical and non-clinical staff) since the study began in June.
Participants took regular tests every two to four weeks and completed questionnaires about symptoms and exposures to the virus every two weeks.
Of the 44 potential reinfections identified in the study, two were rated as “likely” and 42 as “possible”: The term “potential reinfections” is used because none of the 44 potential reinfection cases during the first wave of the pandemic PCR- has been tested. All tested positive for Covid-19 antibodies at the time of enrollment for the study.
After scientists have established that antibody protection lasts an average of five months after infection, they are currently investigating whether protection might last longer.
This analysis came before the widespread spread of the new variant of the virus reported by the UK in December. PHE said, “Work continues in the laboratory to understand if and to what extent antibodies also protect against this variant.”
The study will continue to track participants for 12 months to see how long immunity can last, how effective vaccines are, and the extent to which people with immunity can carry and transmit the virus.