Findings published by Imperial College London and Ipsos MORI show the number of people with COVID-19 antibodies fell by 26.5% over 3 months.
Over 365,000 randomly selected adults tested themselves at home using a finger-prick test between 20 June and 28 September to check if they had antibodies against COVID-19. Over this period, the proportion of people who tested positive for COVID-19 antibodies declined by 26.5%, suggesting antibodies reduce in the weeks or months after a person is infected.
The results suggest that people who did not show symptoms of COVID-19 are likely to lose detectable antibodies sooner than those who did show symptoms. The findings also show the loss of antibodies was slower in 18 to 24 year-olds compared to those aged 75 and over.
‘This study led by Imperial and Ipsos MORI is a critical piece of research, helping us to understand the nature of COVID-19 antibodies over time, and improve our understanding about the virus itself. We rely on this kind of important research to inform our continued response to the disease, so we can continue to take the right action at the right time,’ said Health Minister Lord Bethell.
‘It is also important that everyone knows what this means for them – this study will help in our fight against the virus, but testing positive for antibodies does not mean you are immune to COVID-19. Regardless of the result of an antibody test, everyone must continue to comply with government guidelines including social distancing, self-isolating and getting a test if you have symptoms, and always remember: hands, face, space.’
It remains unclear whether antibodies provide any effective level of immunity or, if such immunity exists, for how long it might last. According to the DHSC, everyone must continue to follow social distancing rules even if they have tested positive for antibodies.
‘Our study shows that over time there is reduction in the proportion of people testing positive for antibodies against the virus that causes COVID-19,’ said Professor Paul Elliott, Director of the REACT programme at Imperial from the School of Public Health.
‘It remains unclear what level of immunity antibodies provide, or for how long this immunity lasts. If someone tests positive for antibodies, they still need to follow national guidelines including social distancing measures, getting a swab test if they have symptoms and wearing face coverings where required.’