A 'herd mentality' can't stop the COVID-19 pandemic. Neither can a weak vaccine.
EARLY DISEASE FIGHTERS, such as Edward Jenner, Louis Pasteur, and William Farr, suspected if enough people were vaccinated, it could eradicate a disease. At the dawn of the 20th century, veterinarians more interested in livestock than people seized on the idea and coined the term “herd immunity.” By the 1920s, clever studies with hundreds of thousands of mice vaulted the idea into the mainstream, stirring optimism that making a fraction of a population immune could forestall a devastating outbreak.
But even the trailblazers researching herd immunity were mystified by how to deploy it in practice. This conundrum has featured in battles against many modern plagues—such as smallpox, polio, and measles. And now it is part of the debate as the COVID-19 pandemic continues to flourish around much of the world.
Some prominent leaders wonder if herd immunity created as people are naturally infected with SARS-CoV-2 coronavirus would be enough to restore society to working order. For evidence, they point to hard-hit epicenters such as New York City, where approximately 20 percent of the residents have been infected and the caseload has been low and steady for months. This sustained recovery must be due to herd protection, they argue.
But based on simple math, past experiences with outbreaks, and emerging evidence from the ongoing pandemic, this claim is a fantasy.
“If we had reached sufficient herd immunity in New York, you would expect incidents to continue going down, not to be holding steady,” says Virginia Pitzer, an epidemiologist at the Yale School of Public Health who specializes in the mathematical modeling of how diseases spread.
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https://www.nationalgeographic.com/science/2020/10/natural-herd-immunity-mentality-cannot-stop-coronavirus-weak-vaccine-cvd/
