A sizable English study showed the sheer number of individuals with Covid-19 antibodies declined significantly throughout the summer, suggesting that having the virus may well not confer long-lasting immunity from future infection.

The survey of 365,000 adults in England who tested themselves in the home using a finger-prick test showed the proportion of men and women testing positive for #Covid-19 antibodies declined by 26.5% between June 20—12 weeks following the peak of infections when looking at the country—and Sept. 28.

The outcome also suggested that folks who did not display symptoms were expected to lose detectable antibodies before they showed symptoms. The analysis, conducted by Imperial College London and Ipsos Mori polling organization, was funded because of the British government, which announced the outcome and published the analysis on Monday night. Other experts have not yet reviewed the outcome.

Doctors do not yet know whether antibodies confer any effective immunity against reinfection by Covid-19. However, just because they are doing, and the link between this survey is confirmed, it suggests the outlook of widespread, long-term herd immunity into the virus should be tough to achieve. Herd immunity occurs when enough people in a population develop an immune response, either through previous infection or vaccination, so the virus cannot spread quickly, and those who are not immune have protection.

The findings showed that 18-24-year-olds lost antibodies at a slower rate than those aged 75 and over. The littlest decline of 14.9% was of men and women aged between 18 and 24 years, together with the largest decline of 29% was of men and women aged 75 and over.

The analysis reflects earlier smaller trials and implies that antibodies into the virus decline over 6-12 months after infection, such as other seasonal coronaviruses, for instance, the common cold. The analysis does not indicate whether other kinds of immune responses—such as that contributed by so-called T cells—would help drive back reinfection.

The analysis showed that 6% of England’s population had antibodies on June 20, compared to 4.4% on Sept. 28. After September, 9% of individuals displayed antibodies in London, compared to just 1.6% in all affected regions when looking at England’s southwest.

Among ethnic groups, 13.8% of Black people tested with antibodies at end-September and 9.7% of Asians—mainly South Asians. This is compared to 3.6% of white people. Minority ethnic groups, when looking at the U.K., such as the U.S., have suffered disproportionately through the virus.
Reference
Study Shows Covid-19 Antibodies Waning Over Time, Suggesting Immunity May Wear Off. https://www.msn.com/en-us/health/medical/study-shows-covid-19-antibodies-waning-over-time-suggesting-immunity-may-wear-off/ar-BB1aqa1Z?li=BBnb7Kz