I became dean of the Colorado School of Public Health in October 2017. When I introduced myself to members of the public, my title often led to puzzlement and questions: What is a dean? What is public health? I soon had rote answers to these questions. For those outside academia, a dean is analogous to the chief operating officer. Answers to the other question required more care. I'm a clinically trained physician (internal medicine and pulmonary medicine) and epidemiologist and have long been describing the public health dimension of my career. Nonetheless, several decades into my career, when I moved from the University of New Mexico to Johns Hopkins to chair the Department of Epidemiology, my father innocently said: “I have always been meaning to ask, just what is epidemiology?” Even, many of my clinical colleagues did not grasp this blending of individual-level care with population-level research and action. But, the combination of public health and clinical care is synergistic, particularly as we more fully grasp the power of the “social determinants of health” in shaping our well-being.


Turning to what is public health, the American Public Health Association explains “Public health promotes and protects the health of all people and their communities.” This definition makes the contrast clear with clinical care, which takes on a population “one person at a time.” The Johns Hopkins Bloomberg School of Public Health has the much envied tagline —“protecting health and saving lives—millions at a time”—which nicely encapsulates public health in a few words.    

Embellishing from my own career as a pulmonary clinician, I frequently made the diagnosis of lung cancer with bronchoscopy, i.e., peering into the lung through a fiberoptic scope. The next step after a lung cancer diagnosis was to hand-off the patient to an oncologist or thoracic surgeon for the possibility of a cure for an aggressive cancer with about 15% five-year survival. Often, when told of the diagnosis, the response from a patient was “doc, was it my cigarettes?” My inevitable answer of “yes” confirmed what the patient already knew, although perhaps had denied for decades.  

As an epidemiologist and public health practitioner, I carried out research on the risks of active and passive smoking, summarized the evidence on smoking in reports of the Surgeon General and the World Health Organization, and supported policies to limit passive smoking and control tobacco use more generally. My clinical work made a difference for some patients, but it has been my public health work on tobacco control that’s had widespread and lasting impacts. For example, I worked on key reports of the US Surgeon General (1986 and 2006) that reached powerful conclusions on secondhand smoke as a cause of disease in nonsmokers. They became the scientific foundation for moving towards smoke-free indoor spaces.   

The work of public health has been described as comprising three essential functions: 1) assessment—gathering and analyzing data to identify problems and paths to solving them; 2) developing and implementing policies to mitigate problems; and 3) assurance—making certain that what needs to happen does happen. Underlying these functions are 10 essential services (Figure 1). It underlies the public health approach generally—at local, state, and national levels. Yet, in the United States, while we refer to the “public health system,” the term is an optimistic misnomer, referring to a fragmented and loosely connected set of entities that do not integrate across the diverse agencies charged with maintaining and advancing public health.

 Figure 1


Deficiencies in public health were laid bare under the stress of the COVID-19 pandemic: inadequate numbers of personnel, some lacking adequate training; antiquated data systems in many jurisdictions, leading to tardy and incomplete epidemic tracking; and inadequate expertise and capacity for using contemporary communications channels, slowing responses to the tsunami of misinformation. The politicization of public health during the pandemic was unprecedented and may be lasting. This month’s appearance of Dr. Anthony Fauci before the House Select Subcommittee on the Coronavirus Pandemic caricatures the political divide around science and public health. As the pandemic progressed, politics became a determinant of what some public health agencies did and how they were supported (or not) by local officials. In a local example, the 75-year-old Tri-County Health Department was dissolved after the politically conservative Douglas County Commissioners withdrew their county because of Tri-County's mask mandate. 

The politicization of public health during the pandemic was unprecedented and may be lasting.

Politicization also affected the public’s response to disease control measures, including the use of masks and other protective gear, and adherence to vaccination recommendations. The politicization had measurable consequences. For example, a study examined excess mortality (mortality beyond that occurring pre-pandemic) in Ohio and Florida between March 2020 and December 2021 by political affiliation (Republican or Democrat). From May 2021 onwards when vaccination was available, the excess death rate among Republican voters was 43% higher than among Democratic voters. This excess could have been reduced by vaccination. In fact, in the United States, an estimated 3 million deaths were prevented during the first two years that COVID-19 vaccination was available. 


In response to lessons learned from the COVID-19 pandemic, there have now been many calls for transformation and re-imagination of public health. With colleagues from Johns Hopkins and Washington University in St. Louis, I co-authored one of the first of these papers, published in the fall of 2020: “Reimagining Public Health in the Aftermath of a Pandemic.” Although the paper was published only eleven months into the pandemic, the vulnerabilities and failings of public health were evident and offered a strong imperative for re-imagination.  We called for the careful assessment of lessons learned and for broad deliberations that would provide a blueprint for transforming our public health system. Reports on the topic have been forthcoming, e.g., from the Commonwealth Fund Commission on a National Public Health System.

More than three years later with even more lessons learned, I revisited the re-imagining of public health with Ross Brownson at Washington University in St. Louis. In a paper just published in Health Affairs, we identified seven areas, categorized as contextual, topical, and technical, that we feel should guide public health transformation. These seven areas are not new as public health matters but need heightened attention with the new insights from the COVID-19 pandemic. In considering priorities, Brownson and I see urgency around the complementary matters of accountability and politicization and polarization. Since public health, when working well is invisible, there needs to be a heightened understanding of the necessity of public health and what it does. Politicization may be reduced by more effective communications to decision-makers, politicians, and the public generally, but new and more powerful messaging is also needed. We fear that the spillover from the politics of the COVID-19 pandemic will reach to fundamental public health measures, including vaccination. Consider the hypothetical arrival of another pandemic caused by an infectious agent in a politicized environment around public health. Political forces could drive strategies away from a grounding in scientific evidence and thwart control measures.   

Since public health, when working well is invisible, there needs to be a heightened understanding of the necessity of public health and what it does.

We also recommended modernization of data systems as a priority, a need made clear by the COVID-19 pandemic. In Colorado, there were challenges in bringing together data from healthcare systems to track the state’s COVID-19 epidemic. For contact tracing, Colorado lacked a system that could be used by its 56 public health agencies, leaving some to resort to manual systems. National reporting was similarly limited, leaving the CDC with lagging data. Fortunately, an innovative team at Johns Hopkins implemented a system that scoured the country for the needed data and made it available on a nearly real-time basis. Our call for data modernization is made at a transformative moment with the emergence of artificial intelligence (AI) as a tool for sorting through massive quantities of data to find the signals that will drive actions. Public health agencies need the systems and tools to capture and analyze data, and sufficient personnel with the skills of cutting-edge data scientists.  

The public health workforce was battered by the COVID-19 pandemic. Already in decline before the pandemic, the public health workforce continues to shrink, losing 40,000 jobs from 2020 to 2023. There is an urgent need to restore the workforce and enhance its skills. Only 14 percent of public health workers hold a public health degree. The Colorado School of Public Health was established in 2008 to provide the trained workforce called for in the Public Health Act of 2008 

The other areas (Table 1) include an addition to the ambit of public health — climate change and health. The consequences of climate change for public health have started: more severe and frequent heat waves and storms, wildfires and worsening ozone air pollution, drought and food insecurity, coastal flooding, and forced migration. These are not new issues, but their severity and immediacy are, as is the need for effective adaptation strategies. Responsibility for some adaptation measures lies with government and within public health agencies: disaster preparedness, heat wave warnings and provision of venues for cooling, and guidance on protection against air pollution and airborne infectious agents, for example. Plus, achieving health equity, a long-standing goal, remains a priority.   

Beyond the article by Brownson and myself, the June issue of Health Affairs contains other perspectives on lessons learned and next steps following the COVID-19 pandemic. They cover judicial decisions, future emergencies, equity, AI, experiences of specific states and institutions, and more. The articles speak to the need for change. Will that change happen? We know what is needed — sustained leadership and enough funding. The immediate imperative of a raging pandemic has faded, however, and the public and politicians, laden by “pandemic fatigue,” may not have the appetite for supporting the needed transformation. I hope that some of the most urgent priorities, highlighted by Brownson and myself, will receive attention. If we flounder when confronted with the next pandemic or other public health crisis, we will again regret not being prepared.

Table 1  

This article is part of a monthly column, The Jon Samet Report, on the biggest issues facing us today in public health, written by the former dean of the Colorado School of Public Health, Jon Samet, a pulmonary physician and epidemiologist, and Professor of Epidemiology and Occupational and Environmental Health. Dr. Samet is a global health leader, shaping the science and conversation on issues ranging from tobacco control to air pollution to chronic disease prevention and more. Each month he shares expert insights on public health issues from local to global.

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The Institute for Science & Policy is committed to publishing diverse perspectives in order to advance civil discourse and productive dialogue. Views expressed by contributors do not necessarily reflect those of the Institute, the Denver Museum of Nature & Science, or its affiliates.