Herd immunity is a dangerous way to go in the fight against COVID-19 | COMMENTARY

Alex Azar, health and human services secretary, who, along with the White House's science adviser Dr. Scott Atlas, met with authors of the so-called Great Barrington Declaration, testifies at a House hearing on Capitol Hill in Washington, Oct. 2, 2020. A manifesto urging reliance on "herd immunity" without lockdowns was warmly received by administration officials, but the strategy cannot stem the pandemic, many experts say.

There has hardly been a shortage of bad ideas of how to manage the COVID-19 epidemic, but one now circulating — community immunity, also known as herd immunity — is arguably the worst. Not only would this “approach” cause millions of deaths worldwide, but it would also fail to provide immunity.

Although the idea of herd immunity has been circulating for a while, it came to a head recently when a group of doctors published what has been come to be known as the Great Barrington Declaration. The group suggested that the U.S. could rapidly achieve herd immunity by letting the COVID-19 virus spread uncontrolled among the young and healthy population while protecting the vulnerable. The widespread use of the term “herd immunity” reflects an ignorance about what the term really means.


Maria Van Kerkhove, an infectious disease specialist from the World Health Organization explained to CNN Health: “Herd immunity is a phrase you use when you use vaccination — when you vaccinate a certain percent of the population to protect the rest of the population that isn’t able to get that vaccine.” Paul Offit, an infectious disease and vaccine expert at the Children’s Hospital of Philadelphia, pulled no punches in an interview with John King of CNN: “Name the virus that eliminated itself by community immunity. It’s never happened. The notion of community immunity by natural immunity is made up.”

Not only is this approach morally abhorrent and dangerous, but it won’t work because of the very nature of SARS-CoV-2, the virus that causes COVID-19. Numerous strains of coronaviruses are currently circulating throughout the world. Despite more than 39 million confirmed cases and over 1.1 million deaths, the infection has yet to burn out. In fact, the opposite is true. Record numbers of cases are now being reported in the U.S. and Europe, and with winter around the corner these numbers will surely rise. When taken together with a small but growing number of confirmed cases of people becoming reinfected, the prospect of community immunity becomes nonsensical.


One only has to look to Sweden to see this “experiment” in practice. Unlike many countries, Sweden chose not to implement strong measures to safeguard its population, but instead, to pin its hopes on herd immunity through widespread infection. Not only has that decision led to much debate over the questionable ethics of this approach, particularly regarding the elderly, but has also led to numerous deaths. According to a recent Time Magazine article, researchers at Johns Hopkins determined that as of Oct. 13, Sweden’s per capita COVID death rate is 58.4 per 100,000 people — the 12th highest in the world. Even more striking are the results of a study published in the Journal of the American Medical Association on Oct. 12. The paper reports, according to Time, that Sweden and the U.S. are the only two countries with high death rates that have completely failed to reduce those rates as the pandemic has continued to progress. Despite this, and the fact that their mortality rate is rapidly increasing, the Swedish government is still trying to sell their approach as a success.

Earlier this week it was widely reported that some in the White House were enthusiastically embracing the idea of trying the same deeply flawed “Swedish option,” even though the science clearly shows that this approach is not feasible. When asked about this idea, Anthony Fauci, the nation’s most prominent infectious disease expert and head of NIH’s National Institutes of Allergy and Infectious Diseases, responded emphatically that it was “ridiculous” and “total nonsense.” We agree.

Adopting such an irresponsible and, to be frank, unethical approach would only lead to massive suffering, an overwhelmed health system, and even more deaths. It clearly hasn’t worked in Sweden and it certainly won’t work anywhere else until a safe and effective vaccine and/or drugs can be developed that can be used by the majority of the population. Only through these means will the goal of achieving herd immunity have any chance of being safely and successfully accomplished.

Katherine Seley-Radtke ( is a professor of chemistry and biochemistry at the University of Maryland, Baltimore County. Josh Bloom ( is the director of chemical and pharmaceutical science at the American Council on Science and Health.