Coronavirus: British study finds evidence of waning immunity over time
- Scientists at Imperial College London tracked antibody prevalence in UK population and found it fell by a quarter over three months
- Findings do not necessarily have implications for efficacy of vaccine candidates, as good vaccine could be better than natural immunity
Antibodies against the novel coronavirus declined rapidly in the British population during the summer, a study found on Tuesday, suggesting protection after infection may not be long lasting and raising the prospect of waning immunity in the community.
Scientists at Imperial College London have tracked antibody levels in the British population following the first wave of Covid-19 infections in March and April.
Their study found that antibody prevalence fell by a quarter, from 6 per cent of the population around the end of June to just 4.4 per cent in September. That raises the prospect of decreasing population immunity ahead of a second wave of infections in recent weeks that has forced local lockdowns and restrictions.
Although immunity to the novel coronavirus is a complex and murky area, and may be assisted by T cells, as well as B cells that can stimulate the quick production of antibodies following re-exposure to the virus, the researchers said the experience of other coronaviruses suggested immunity might not be enduring.
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“We can see the antibodies and we can see them declining and we know that antibodies on their own are quite protective,” Wendy Barclay, head of the Department of Infectious Disease at Imperial College London told reporters.
“On the balance of evidence I would say, with what we know for other coronaviruses, it would look as if immunity declines away at the same rate as antibodies decline away, and that this is an indication of waning immunity at the population level.”