Study Shows Covid-19 Antibodies Waning Over Time, Suggesting Immunity May Wear Off - msnNOW

LONDON—A large English study showed the number of people with Covid-19 antibodies declined significantly over the summer, suggesting that getting the virus might not confer long-lasting immunity from future infection.

The survey of 365,000 adults in England who tested themselves at home using a finger-prick test showed the proportion of people testing positive for Covid-19 antibodies declined by 26.5% between June 20—12 weeks after the peak of infections in the country—and Sept.

The results also suggested that people who didn’t display symptoms were likely to lose detectable antibodies before those who had showed symptoms.

Herd immunity occurs when enough people in a population develop an immune response, either through previous infection or vaccination, so that the virus can’t spread easily and even those who aren’t immune have protection.

The findings showed 18-24-year-olds lost antibodies at a slower rate than those aged 75 and over.

The study reflects earlier smaller trials and suggests that antibodies to the virus decline over 6-12 months after infection, as in other seasonal coronaviruses such as the common cold.

The study showed 6% of the population of England had antibodies on June 20, compared with 4.4% on Sept.