In the final weeks of his reelection campaign, U.S. President Donald Trump vacillated between promising that a coronavirus vaccine would soon be widely available and claiming that the pandemic was already over. On October 27, his Office of Science Technology and Policy put out a statement that listed “ending the COVID-19 pandemic” as a crowning achievement of his first term. In fact, the virus continues to spread unchecked throughout the United States. And now that Election Day has come and gone without a vaccine, it is clear that Trump’s real strategy for confronting the disease is to simply surrender.  

The president’s effort to accelerate the development of a vaccine, Operation Warp Speed, will likely continue, but the goal of universal immunization appears to have fallen by the wayside. Key Trump advisers, including Dr. Scott Atlas, a member of the president’s coronavirus task force, have reportedly embraced a de facto strategy of herd immunity—or “herd mentality,” as Trump put it during a recent town hall event—through widespread natural infection. Atlas denies that the White House has adopted such a strategy, but it is clear from his public statements on social media and to the press that this is precisely what he has recommended. Trump, meanwhile, has promised that herd immunity is “going to happen.” This strategy has been widely criticized by public health scientists, including myself, since it would likely result in the death or permanent disability of millions of Americans.

Former Vice President Joe Biden has put forward a detailed, seven-point plan for tackling the pandemic that contrasts sharply with Trump’s approach. It is scientifically driven and draws on his extensive experience battling infectious disease during his eight years as vice president. In addition to providing clear and evidence-based national guidance, including a mandate for masks, Biden has pledged to invest $25 billion in manufacturing and distributing vaccines—not just to vulnerable populations but to every American. The end goal of Biden’s plan is the same as Trump’s plan—herd immunity—but through immunization, not natural infection. In the coming days or weeks, Americans will learn which path their votes have put them on.


A population is said to have achieved herd immunity to a pathogen when enough people have become immune that the pathogen can no longer find susceptible hosts. Viral pathogens are unable to reproduce on their own and do not last indefinitely in nature. If they cannot find a host, they will eventually sputter out and be eliminated from the population.

Herd immunity to viral disease has been achieved on a national or global scale only through immunization. The natural spread of viral diseases such as polio and smallpox has conferred immunity on smaller populations, but it wasn’t until the advent of vaccines that these diseases were eliminated from national or global populations. In less than a decade in the1960s, widespread polio vaccination decreased the overall incidence of paralytic poliomyelitis from thousands of cases per year to zero. Similarly, an intensive global vaccination campaign enabled the World Health Organization to declare smallpox eradicated in 1980.

Yet the notion that widespread natural infection might yield herd immunity to viral pathogens has endured on the fringes of the scientific and public health communities, despite the lack of historical precedent. This idea was the implicit basis for Sweden’s relatively relaxed coronavirus response. It also undergirds the so-called Great Barrington Declaration, a proposal for reaching herd immunity put forward by the libertarian American Institute for Economic Research that has attracted the vocal support of Atlas and others in the Trump administration. The Great Barrington Declaration calls for “focused protection” of vulnerable people at high risk of severe COVID-19 while encouraging young, healthy people to take no precautions against exposure, resulting in widespread infection and, eventually, herd immunity.

Trump's strategy would likely result in the death or permanent disability of millions of Americans.

This strategy is misguided and doomed to fail, which may be why it is conveniently light on details about how the administration might implement it. To begin with, if vulnerable people were defined by all COVID-19 risk factors, including age, male sex, diabetes, heart disease, obesity, and chronic respiratory diseases such as asthma, more than half the population would need “focused protection.” Such an effort would require enormous public investment, and it might not even leave enough young, healthy (and unprotected) people to reach the threshold for herd immunity.

In addition, these young and healthy people could end up suffering lasting health problems as a result of COVID-19. Although the long-term consequences of the disease are largely unknown and are an active area of research, early findings indicate they can be serious even in people with mild cases. A growing body of evidence suggests that these patients can suffer serious neurological impairment, inflammation of the heart, and acute lung injury. In other words, the young, healthy people who would enjoy the benefits of herd immunity under the Great Barrington Declaration policy may also suffer chronic, debilitating disease.     


Biden’s plan to reach herd immunity through the tried-and-tested method of immunization would likely save hundreds of thousands if not millions of lives. Until a vaccine can be widely distributed, the plan seeks to curb transmission through the clear communication of evidence-based public health guidelines—a strategy that was clearly informed by Biden’s experience battling epidemics during his tenure as vice president.  

In the spring of 2009, just months after Biden and President Barack Obama took office, an influenza pandemic swept across the border from Mexico and began to spread rapidly in the United States. In an interview on NBC’s Today show that in hindsight seems remarkably prescient, Biden said he would discourage friends and family from flying, riding the subway, or spending long periods of time in confined spaces. The Obama administration immediately walked these comments back, fearing that they would invite panic, and instead reassured the public that the nation’s health agencies were responding and that a vaccine was being developed. These mixed messages caused confusion that, combined with later missteps related to the timing and rollout of the vaccine, likely contributed to the spread of the H1N1 virus.

The Obama administration mounted an aggressive campaign to develop and distribute vaccines, but unexpected laboratory delays set its timeline back by months. Producing influenza vaccines typically requires growing the virus in embryonated chicken eggs. The H1N1 virus grew more slowly in eggs than expected, however, slowing the production of vaccines and delaying their distribution to the public. Additional manufacturing setbacks delayed the process further, as did confusion about the dosing regimen. As a result, the administration delivered less than half of the 100,000 doses it had promised by October, and demand for them far exceeded supply throughout the fall of 2009.

Biden’s plan to reach herd immunity through immunization would likely save hundreds of thousands of lives.

Ultimately, the 2009 H1N1 virus infected 60 million Americans and caused approximately 14,000 deaths. Ron Klain, Biden’s chief of staff during the 2009 pandemic, famously remarked in 2019 that it was sheer luck that prevented H1N1 from causing mass casualties—a quip that Trump seized on during the campaign and framed as an example of Biden’s “disastrous” pandemic response. That is a false interpretation of events. Biden could not have solved the vaccine development issues that caused the delays. But the Obama administration’s conflicting messages about preventative measures and its failure to deliver the vaccine on time and in the quantities needed did erode public confidence in the federal response. The 2009 H1N1 pandemic was a lesson in the importance of clear, evidence-based communications to bolster trust in scientific and medical experts, since even the most well-laid, seemingly foolproof plans can go wrong during a public health crisis.

Biden had an opportunity to put those lessons into practice during the Ebola epidemic that ravaged West Africa between 2014 and 2016, infecting nearly 30,000 people and killing 11,000. The Obama administration installed Klain as its Ebola “czar” in October 2014, a week after Thomas Eric Duncan, a Liberian citizen visiting family in Dallas, became the first Ebola patient to die in the United States. Biden successfully pushed Congress to pass a $5.4 billion emergency funding package that supported efforts to fight Ebola abroad and sped up trials of Ebola vaccines that had been stuck in preclinical testing.

This time around, there was no muddled messaging about the dangers of Ebola to the public. Both Biden and Klain relied on trusted public health officials, including Dr. Anthony Fauci and Dr. Tom Frieden, then the director of the Centers for Disease Control and Prevention, to communicate with the public and to let the science drive the response. Ebola never gained a foothold in the United States and was eventually contained in West Africa. In 2019, the U.S. Food and Drug Administration granted full approval to one of the vaccines that was funded in part by the aid package Biden championed.


Biden’s plan to tackle COVID-19 emphasizes three overarching lessons from these prior public health crises: listen to science; ensure public health decisions are informed by public health professionals; and restore trust, transparency, and accountability in government. The goal is to achieve herd immunity through universal immunization. But until a vaccine is available, a Biden administration would focus on minimizing transmission—through a nationwide mask mandate, improved testing and contact tracing, and efforts to protect high-risk Americans.

This approach could not be more different from Trump’s apparent plan to reach herd immunity through negligent inaction. Given his recent comments on the campaign trail, there is little doubt that he is resigned to letting the virus spread unchecked through the American population. The Biden plan also aims for herd immunity, but without paying the unacceptable price of hundreds of thousands of American lives.

You are reading a free article.

Subscribe to Foreign Affairs to get unlimited access.

  • Paywall-free reading of new articles and a century of archives
  • Unlock access to iOS/Android apps to save editions for offline reading
  • Six issues a year in print, online, and audio editions
Subscribe Now