People who have COVID-19 have very high immunity to it for at least five months, but there is evidence that people who have antibodies are still able to carry and spread the virus. May, a study of British healthcare workers has found.

Preliminary findings from scientists at Public Health England (PHE) showed that infection is rare among people who have COVID-19 antibodies from previous infections – the study found only 44 cases out of the 6,614 people previously infected. went.

But experts cautioned that the findings meant that people who contracted the disease in the first wave of the epidemic in the early months of 2020 may now catch it again.

He also warned that people with so-called natural immunity – those who had gained through the infection – may still be able to carry the SARS-CoV-2 coronavirus to their nostrils and throat and pass it unknowingly. .

PHE senior medical adviser Susan Hopkins said, “We now know that most of the people who had the virus, and developed antibodies, are protected from re-infection, but it’s not total and we don’t know yet Is how long it lasts. ” The study’s co-leaders, whose findings were published on Thursday.

“This means that even if you believe you already had the disease and you are safe, you can still be assured that you will not develop serious infections. But there is still a risk that you will get the infection Can do it and pass it on to others. “

Major implications

Experts are not directly involved in the research, known as the SIREN study, urging people to note its important findings.

Eleanor Riley, a professor of immunology and infectious disease at Edinburgh University, said, “These data confirm the message that, everyone is a potential source of infection for others and should behave accordingly.”

Simon Clarke, an associate professor of cellular microbiology at Reading University, said the study has major implications for how we can get out of the current crisis.

“This means that the vast majority of the population will either need to have natural immunity or be vaccinated to fully lift the restrictions on our lives, until we see many more people getting infected and dying of COVID-19 Are not prepared for, ”she said.

PHE said in a statement that the study was not able to detect antibodies or other immune responses to COVID-19 vaccines being rolled out in the UK. Vaccine effects will be studied later this year as part of SIREN.

The SIREN study involves thousands of health care workers in the UK who have been tested regularly since June for new COVID-19 infections as well as the presence of antibodies.

Between 18 June and 24 November, scientists found 44 possible infections out of 6,614 participants – two “probable” and 42 “possible” – who tested positive for antibodies. He said that this represents an 83% rate of protection from reinfection.

Researchers said they would continue to follow participants to see if this natural immunity could last longer than five months in some. But he said preliminary evidence from the next phase of the study suggests that some people with immunity may still carry high levels of the virus.