People who have contracted COVID-19 could be immune from reinfection for up to six months, according to a new study in the United Kingdom.
Researchers at U.K. Biobank who collected monthly blood samples from approximately 20,200 participants found that those who contracted the virus exhibited high levels of antibodies for up to half a year. Reinfection during this time period is not likely among most patients, according to a readout.
“The vast majority of people retain detectable antibodies for at least six months after infection with the coronavirus,” said Naomi Allen, chief scientist at U.K. Biobank.
From May 27 to Dec. 4, 18,893 people (93.5%) in the study provided at least one sample that was successfully analyzed at the Target Discovery Institute. A total of 705 participants produced a blood sample that was seropositive for COVID-19, meaning they contracted the disease. Participants ranged in age from under 30, with 2,050 people, to 70 and over, with 3,998 participants.
The findings indicated the possibility of protection against the disease after infection for several months. Results showed 99% of the participants who previously contracted the virus retained antibodies to SARS-CoV-2 for three months. After six months, 88% of the participants still retained the antibodies.
“Although we cannot be certain how this relates to immunity, the results suggest that people may be protected against subsequent infection for at least six months following natural infection,” Allen said, adding that the findings in her group’s study were consistent with another research project conducted elsewhere in the U.K. and with a study in Iceland.
James Bethell, a health minister for the British Parliament, lauded the study for offering “some promise” of hope amid the pandemic, but he urged people to remain cautious in public life, as even those with antibodies could still be carriers who contribute to the spread of the virus.
“Right now, it remains vital for everyone to stay at home, even if you have had COVID-19 in the past, so we can stop the spread of the virus, protect the [National Health Service], and save lives,” Bethell said.
According to Johns Hopkins University COVID-19 data, the U.K. has reported over 3.8 million virus cases since the outset of the pandemic, with nearly 109,000 fatalities attributed to the disease. So far, 476,298 people have been fully vaccinated in the country, representing 0.72% of the population.
