London:
People with asymptomatic coronaviruses appear to lose detectable antibodies earlier than people who have exhibited symptoms of Covid-19, according to one of the largest such studies in Britain published on Tuesday.
Results from Imperial College London and market research firm Ipsos Mori also suggest that antibody loss was slower among 18-24 year olds than among those 75 and over.
Overall, samples from hundreds of thousands of people across England between mid-June and the end of September showed that the prevalence of viral antibodies had fallen by more than a quarter.
The research, commissioned by the British government and released by Imperial on Tuesday, indicates that people’s immune response to Covid-19 wanes over time after infection.
James Bethell, a young Minister of Health, called it “critical research, helping us understand the nature of Covid-19 antibodies over time.”
But the scientists involved have warned that much remains unknown about people’s long-term antibody response to the virus.
“It is still not clear what level of immunity antibodies provide, or how long that immunity lasts,” said Paul Elliott, of the Imperial School of Public Health.
The study involved 365,000 randomly selected adults administering three sets of fingerprick tests for antibodies to the coronavirus at home between June 20 and September 28.
The results showed that the number of people carrying antibodies dropped 26.5% over the period of about three months.
Nationally, that means the proportion of the UK population with antibodies has risen from 6.0% to 4.4%, according to the study.
The drop coincided with the dramatic drop in the prevalence of the virus in England – and the rest of Britain – after a multi-month nationwide shutdown that was eased over the summer.
However, research has found that the number of healthcare workers testing positive for antibodies has not changed over time, which may reflect repeated or higher initial exposure to the virus.
“This very large study has shown that the proportion of people with detectable antibodies decreases over time,” said Helen Ward, one of the lead authors.
“We do not yet know if this will put these people at risk of re-infection with the virus that causes Covid-19, but it is essential that everyone continue to follow the advice to reduce the risk to themselves and to others.
(Except for the title, this story was not edited by GalacticGaming staff and is posted from a syndicated feed.)