During a pandemic, no one’s health is fully in their own hands. No field should understand that more deeply than public health, a discipline distinct from medicine. Whereas doctors and nurses treat sick individuals in front of them, public-health practitioners work to prevent sickness in entire populations. They are expected to think big. They know that infectious diseases are always collective problems because they are infectious. An individual’s choices can ripple outward to affect cities, countries, and continents; one sick person can seed a hemisphere’s worth of cases. In turn, each person’s odds of falling ill depend on the choices of everyone around them—and on societal factors, such as poverty and discrimination, that lie beyond their control.
Across 15 agonizing months, the COVID-19 pandemic repeatedly confirmed these central concepts. Many essential workers, who held hourly-wage jobs with no paid sick leave, were unable to isolate themselves for fear of losing their livelihood.
…“From the very beginning, I’ve thought that the way we’ve dealt with the pandemic reflects our narrow focus on the individual,” Camara Jones, a social epidemiologist at Morehouse School of Medicine, told me. Testing, for instance, relied on slow PCR-based tests to diagnose COVID-19 in individual patients. This approach makes intuitive sense—if you’re sick, you need to know why—but it cannot address the problem of “where the virus actually is in the population, and how to stop it,” Jones said. Instead, the U.S. could have widely distributed rapid antigen tests so that people could regularly screen themselves irrespective of symptoms, catch infections early, and isolate themselves when they were still contagious. Several sports leagues successfully used rapid tests in exactly this way, but they were never broadly deployed, despite months of pleading from experts.
…In the early 19th century, European researchers such as Louis-René Villermé and Rudolf Virchow correctly recognized that disease epidemics were tied to societal conditions like poverty, poor sanitation, squalid housing, and dangerous jobs. They understood that these factors explain why some people become sick and others don’t. But this perspective slowly receded as the 19th century gave way to the 20th.