Herd immunity could be disastrous | Daily News


 

Herd immunity could be disastrous

Since the coronavirus pandemic began, herd immunity has been floated by some experts as a possible solution to the deadly virus that has so far killed over 865,000 people worldwide.

Herd immunity is possible when enough people have contracted and become immune to a virus, providing community-wide protection by limiting the number of people who can spread it. And while the strategy is considered controversial and even downright dangerous by many public health experts, it is also reportedly gaining momentum in the White House.

According to a report by the Washington Post, herd immunity is a strategy being pushed by Dr. Scott Atlas — a neuroradiologist with no background in infectious diseases or epidemiology who recently joined the White House as a pandemic adviser.

Atlas denied that he had encouraged the White House to adopt a herd immunity strategy, and on Wednesday White House coronavirus task force coordinator Dr. Deborah Birx and top infectious disease expert Dr. Anthony Fauci dismissed the idea that herd immunity was under consideration. An administration official, however, told CNN that the policies being promoted by Atlas are indeed akin to a herd immunity approach.

Ordinarily, herd immunity would be acquired through a majority of the population being vaccinated — not through immunity acquired by natural infection.

“Normally, when we talk about herd immunity, we talk about how much of the population needs to be vaccinated,” World Health Organization (WHO) COVID-19 technical lead Dr. Maria Van Kerkhove said on Aug. 27. “If we think about herd immunity in a natural sense of just letting a virus run, it's very dangerous because you would need a lot of people to be infected.”

It’s still uncertain what percentage of a population would need to be immune to the virus in order to attain herd immunity. According to Johns Hopkins University, in general, the answer is 70 to 90 percent of a population, depending on how contagious the infection is. But a model published last month in the magazine Science found that the threshold needed for coronavirus herd immunity could be as low as 43 percent.

Proponents of herd immunity have looked to emulate Sweden’s more hands-off approach; unlike most countries in Europe, the Nordic country opted out of a nationwide lockdown and kept most businesses open.

But Sweden’s strategy didn’t entail a total return to normalcy. The Swedish government implemented a ban on gatherings of 50 people or more, and many Swedes voluntarily followed social distancing guidelines.

Former FDA Commissioner Scott Gottlieb noted in an op-ed published on Aug. 30 that in addition to being much larger than Sweden (a country with a population the same size as North Carolina’s), the U.S. has a high rate of citizens with preexisting conditions, which can lead to a higher rate of COVID-19 complications; about 10 percent of Americans have diabetes, and 40 percent are considered obese.

Moreover, Sweden’s pursuit of natural herd immunity doesn’t appear to be working. A study released in June by the country’s Health Agency showed that only 6 percent of Swedes had developed antibodies to the coronavirus — though a recent study from Sweden’s Karolinska Institute and Karolinska University Hospital suggests that immunity in Sweden may be higher than antibody tests indicate.

The role of antibodies and how much of an impact they have on long-term immunity is still questionable. A U.K. study, which had not yet been peer-reviewed, found that antibodies may start to decline 20 to 30 days after the onset of COVID-19 symptoms. And a Chinese study found that antibody levels in patients who had recovered from COVID-19 fell sharply within two to three months after infection.

Falling antibody counts may not necessarily mean waning immunity; other immune responses such as T-cells could also affect how long immunity lasts. (Yahoo)


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