Researchers Blast 'Dangerous' COVID-19 Herd Immunity Strategy

Any so-called "herd immunity" strategy based on letting coronavirus infections spread unchecked is not only dangerous, but completely unsupported by scientific evidence, said researchers in an open letter to The Lancet.

Not only is there no proof of lasting immunity to SARS-CoV-2 following natural infection, but the strategy would place an unacceptable burden on healthcare workers, as well as the economy, wrote Deepti Gurdasani, MD, PhD, of Queen Mary University of London, who was joined by more than 80 researchers.

"Such an approach also risks further exacerbating the socioeconomic inequities and structural discriminations already laid bare by the pandemic," the authors wrote in the letter, titled "Scientific consensus on the COVID-19 pandemic."

Long dismissed by public health officials as untenable, herd immunity through natural infection gained traction recently, thanks to a call by Trump administration officials promoting the strategy as described in the "Great Barrington Declaration." The document argues against lockdowns and for full reopenings, including mass gatherings and total in-person work and school, while "the vulnerable," who were not defined, are the only ones who need to stay at home.

The Infectious Diseases Society of America (IDSA) and the HIV Medicine Association (HIVMA) already "strongly denounced" the herd immunity strategy, saying it comes "without data or evidence."

"To assert that stepping away from the vigilance needed to control the spread of this novel coronavirus and that abdication of efforts to control a pandemic that has overwhelmed health systems worldwide is a 'compassionate approach' is profoundly misleading," said IDSA president Thomas File, MD, and HIVMA chair Judith Feinberg, MD, in a statement.

Gurdasani and colleagues took issue with the idea of "protecting the vulnerable," noting that not only is defining who we see as vulnerable complex, but those at risk of COVID-19 comprise nearly 30% of the population in some places. Isolating that many people is "practically impossible and highly unethical," the authors wrote.

This strategy, which suggests uncontrolled outbreaks in a low-risk population would lead to "infection-acquired population immunity," risks significant morbidity and mortality across the world, they added. "Empirical evidence from many countries shows that it is not feasible to restrict uncontrolled outbreaks to particular sections of society."

The Lancet authors warned that in order to prevent future lockdowns, continued restrictions will likely be needed in order "to reduce transmission and fix ineffective pandemic response systems."

Noting that Japan, Vietnam, and New Zealand were able to stamp out COVID-19 outbreaks with a robust public health response, they argued that controlling community spread of COVID-19 "is the best way to protect our societies and economies" until safe and effective vaccines and treatments are available.

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