The SIREN analysis examined the impression of an infection on greater than 20,000 volunteer well being staff from throughout the UK and a pre-print of the examine discovered solely 44 circumstances amongst 6,614 folks.
Two teams of individuals, one with no proof of earlier an infection and the opposite with proof of previous an infection, had been adopted for as much as six months.
The examine — which has not but been peer reviewed — concluded that previous an infection reduces the probabilities of catching the virus once more by 83% for a minimum of 5 months.
The cohort had been examined usually for Covid-19.
“About 6,000 of the healthcare workers were people who had evidence of having had SARS-CoV-2 infection… and about 14,000 of the healthcare workers were people who had no evidence of previous SARS-CoV-2 infection,” Tom Wingfield, senior medical lecturer on the Liverpool School of Tropical Medicine, informed the UK’s Science Media Centre.
“The findings suggest that re-infection rates in the positive cohort were 83% lower than the negative cohort during the follow-up period.”
But researchers warned that the safety was not complete and that it was unclear how lengthy any immunity lasts. It can be attainable that those that have a level of immunity towards the virus should still have the ability to transmit it to others.
“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,” Susan Hopkins, senior medical adviser at PHE and co-leader of the examine, stated in keeping with Reuters.
“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 you could acquire an infection and transmit (it) to others,” Hopkins stated.
Hopkins emphasised the purpose throughout an interview with the BBC’s Today program on Thursday.
“[Infection] reduces your risk by at least 80%….but it doesn’t eliminate it,” she stated.
“We found people with very high amounts of virus in their nose and throat swabs, that would easily be in the range which would cause levels of transmission to other individuals.” Hopkins burdened that individuals who had beforehand caught Covid-19 nonetheless wanted to obey social distancing guidelines to keep away from transmitting the illness.
England is at present underneath a stringent nationwide lockdown after circumstances surged over the vacation interval. The UK has recorded greater than 3.2 million circumstances of an infection.
“What [the study] really highlights is that immediately after infection you probably have a high level of protection but that will decay over time,” Niall Ferguson, a number one epidemiologist at Imperial College London, additionally informed the BBC.
“Transmission now is slower than it would have been in the absence of people getting infected and those people who’ve had the virus before are at less risk of getting infected — and that cumulatively is slowing spread.”
“This study supports the hypothesis that primary infection… provides a high degree of immunity to repeat infection in the short to medium term; with similar levels of prevention of symptomatic infection as current licensed vaccines for working age adults,” the PHE report notes.
“Primary infection also reduces the risk of asymptomatic infection and thus onward transmission; this is particularly important in [that]… healthcare was considered as a potential driver for ongoing community transmission in Wave 1 in the UK.”
The researchers will proceed to check antibody responses to an infection and the impression of Covid-19 vaccines.