COVID19: United Kingdom study dispels herd immunity theory

Henrietta Strickland
October 28, 2020

Serological tests involve testing the patient's blood for antibodies of a virus.

The tests are supplied by Whitmire Medical and are available to Kroger customers for $25 and can provide results within 15 minutes.

World Health Organization spokesman Tarik Jasarevic said that uncertainty over how long immunity would last, and the fact that most people had never had antibodies against the coronavirus in the first place, showed the need to break transmission chains.

A study conducted in the United Kingdom found that during the summer, antibodies against the novel coronavirus rapidly declined in the British population, a report by Reuters revealed.

The study verifies an observation that other studies have shown, namely, that infection with the coronavirus may not confer "durable immunity", meaning long-lasting immunity, on patients.

"This very large study has shown that the proportion of people with detectable antibodies is falling over time", said Helen Ward, professor at Imperial College London.

And while these findings are significant, researchers say that the number of participants who took supplements is still too small, making it hard to draw any solid conclusions from this study.

Researchers of this particular study describe being deficient in vitamin D as having levels lower than 20ng/mL, which can be determined with a blood test.

The evidence follows several studies published earlier this year from China, the United Kingdom and the U.S., which found that people's antibody levels declined sometimes as early as two months after infection.

The study, which has not yet been peer reviewed to flag flaws, backs up findings from similar surveys in Germany.

Of course, even testing positive for antibodies is no guarantee that one is immune.

Antibodies would be expected to decline over time, as they do with other coronaviruses, like the common cold, but how fast and how far they fall is unknown for Covid-19. Vaccines contain immune stimulators, which she says induce durable immune responses in ways that can be different to natural infection. Rowland Kao, from the University of Edinburgh, thinks the data is evidence a herd immunity strategy lacks credibility.

He added, "Herd immunity is a more general concept, but when people use the term they often mean herd protection; which is the point where there is so much immunity in the population that a community would not be able to start an epidemic if someone in that community got infected". "This study provides evidence that the level of immune response has declined over a relatively short period (three months) indicates that such future planning can not take for granted the beneficial effects of previous infection - importantly, should the results of this study prove robust, this implies that any strategy that relies on "herd immunity" lacks credibility".

Other reports by Click Lancashire

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