For much of human history, infectious diseases were the main causes of morbidity and mortality. The sciences of public health, epidemiology, microbiology, and vaccine and drug development have dramatically reduced the risks associated with these diseases such that
life expectancies in high income countries have increased by close to 40 years over the last century, principally due to a reduction in child deaths from infectious diseases. Today, chronic diseases are the main cause of mortality and are expected to increase over time.
However, epidemic and pandemic outbreaks still pose formidable risks to human life. The COVID-19 pandemic, for example, reduced life expectancy in the United States
by more than 2 years from 2019-21, and increasing population size, dense urbanization, global travel, climate change, and pressure on ecological systems are making epidemic outbreaks more common. Recent studies have estimated the probability of another pandemic of the magnitude of COVID-19 occurring in the next 25 years
to be about 50%.
I was thus shocked to see a
recent article penned by the director of the National Institutes of Health, Jay Bhattacharya, and his principal deputy director, Matthew J. Memoli, which proposed a radical new approach to pandemic preparedness that focuses on individual health decisions while rejecting traditional, evidence-based community public health practices. In the article, the authors argue that “a metabolically healthy population, physically active and eating nutritious food, will cope far better in the face of a novel pathogen than a population facing a severe chronic-disease crisis.” They maintain that “simply by stopping smoking, controlling hypertension or diabetes, or getting up and walking more, anything that makes the population healthier will prepare us better for the next pandemic.” Meanwhile, traditional approaches to pandemic preparedness, they write, waste money and create a “false sense of security and empower those who would impose lockdowns, mandates, and other such strategies.”
As a public health physician, I welcome any initiatives aimed at improving a population’s health status and agree that such practices will likely reduce morbidity, especially from chronic diseases, and may help people recover more quickly from infectious diseases. However, calling for a metabolically healthy population is wholly insufficient as a policy for preparing for future pandemics.
While it is true that individuals with co-morbidities such as hypertension, obesity, and diabetes tended to experience worse outcomes from COVID-19, this has not been the case for other infectious threats. The great influenza pandemic of 1918, for example, had particularly high excess mortality rates in the young with
more than half of the deaths in young adults 20-40 years of age, including in military recruits at the peak of their physical fitness. And smallpox, which is estimated to have ended the lives of between
300 and 500 million people in the 20th century, killed the non-immune indiscriminately with the vast majority of deaths occurring in unvaccinated infants and children. Better metabolic fitness might have improved outcomes for healthier people relative to those with chronic illness in these cases, but it would not have prevented excess deaths in otherwise healthy individuals. Furthermore, metabolic risk factors are very common in the US, where the prevalence of
adult hypertension is 47.7%,
obesity is 40.3%, and
diabetes is 14.7%. It is thus unlikely that these could be easily resolved at a population level as a pandemic prevention mechanism.
Contrary to Bhattacharya and Memoli’s characterization, active surveillance for novel diseases and infectious agents is essential in every country in the world. We do not know where the next epidemic will begin nor with what type of infectious agent. Having a warning system in place will enable early detection, identification, and response, allowing the critical work of producing specific interventions to begin as soon as possible.
Systems to produce and deliver medical countermeasures when an epidemic is detected are also vital. Diversifying the manufacturing of countermeasures will help assure access to any therapeutic agents that are developed, while enhancing primary health care systems and assuring access to these systems—even for the most isolated communities—will allow early detection of novel agents. Such systems are also critical for delivering interventions, whether they be health education; non-specific strategies such as masking, handwashing, and isolating ill persons; or the distribution of preventative or therapeutic agents.
Most importantly, we need science to continue to improve our prevention technologies, especially the speed with which they can be developed. We live in a world that is at increasing risk of “poly-epidemics”—health crises with many dimensions and exacerbating factors. So, when we face highly lethal threats, such as a fast-moving, high-mortality respiratory epidemic, every minute of improvement in the timeline of development of medical countermeasures counts. Remarkably,
we had an emergency-authorized COVID-19 vaccine for general use within 327 days of the SARS-CoV-2 virus being sequenced, primarily because of decades of work on developing mRNA as a platform to effectively deliver antigens.
Immunization using mRNA technology is not a silver bullet and may not always be the best approach, but in our current armamentarium, there is no faster way to make a vaccine. The Moderna COVID-19 vaccine was
designed and delivered to the NIH in a vial 44 days after the sequence of the virus was published online and was injected into the first volunteer 21 days later. It could be done even faster today. And speed needn’t mean compromises in safety. In the case of COVID-19, scientists, industry, regulatory agencies, and 30,000 -40,000 clinical trial volunteers worked together to ensure that the vaccines were tested in large numbers of people and demonstrated to be safe before they were made widely available.
But magical thinking isn’t only happening in research and development. On 5 December 2025, the newly constituted Advisory Committee for Immunization Practices (ACIP) at the Centers for Disease and Prevention (CDC), voted to drop the decades-old universal hepatitis B vaccine birth dose recommendation without any new evidence of harm and ignoring clear benefits. Not coincidentally, the current roster of ACIP members includes vaccine skeptics and non-experts who were hand-picked by the US Secretary of Health and Human Services, Robert F Kennedy Jr.—himself a known vaccine skeptic—who has claimed
without scientific evidence that the hepatitis B shot causes autism.
One of the arguments made by the ACIP panel is that Denmark does not require the birth dose unless a mother is known to be positive for hepatitis B. Denmark is a small, homogeneous population with a universal health system that ensures that the population is tested for hepatitis B and provided with adequate care. The experience in the US is more heterogeneous. All pregnant women are supposed to be screened for hepatitis B at their first prenatal visit, but
18% of women in the US are not tested for the virus during pregnancy and only 35% of women of women who test positive receive all recommended follow up care.
The exact prevalence of hepatitis B in the US is unknown, with estimates between
660,000 and
2.2 million people. As many as
50% are unaware of their infection status, meaning that universal immunization to create population immunity is the best way to protect the population and to eliminate maternal-infant hepatitis B transmission. Hepatitis B vaccination at birth also protects children from infection through contact with infected caregivers and household members as well as in other settings which—prior to 1991—accounted for a
substantial number of infections.
As a physician who was a volunteer in the original efficacy trial for the recombinant hepatitis B vaccine in the mid-1980s, I have a particular interest in this vaccine and have followed it closely. It is exceedingly safe and highly efficacious.
The current administration’s rejection of evidence-based public health policies recently led 12 former commissioners of the US Food and Drug Administration (FDA)—appointed by both Democratic and Republican administrations—to express concern about
vaccine policy and public health security at the agency. Nine former CDC directors have similarly argued that Kennedy, specifically, is
endangering the health of Americans, with six former Surgeon Generals
joining their call.
Rejecting evidence-informed infectious disease strategies and undermining vaccine-based interventions will not make us healthy again. Given the influence the US has in the world, medical misinformation and disinformation is also likely to increase vaccine hesitancy globally.
Magical thinking has no place in public health. Every scientist and health care provider has a duty to speak up against these misguided policies and positions.