When Public Schools Served as Vaccine Trial Sites

Time and again, the spread of life-threatening illnesses has caused widespread panic and a race to find a cure or vaccine—especially when disease strikes the most vulnerable populations, like children. 

In the 1920s, the bacterial infection diphtheria resulted in thousands of deaths each year, with the illness primarily affecting children under 5 years old. When polio cases spiked in the mid-20th century, images of paralyzed children in newspapers stoked unprecedented levels of fear among parents. By the 1960s and 1970s, measles—less deadly but still highly contagious—struck almost all children before the age of 15 years old.

In all these cases, public schools played a unique role for major trials of novel vaccines. At the height of the polio epidemic, many parents were more than willing for their children to participate for the sake of their health. But societal attitudes toward the use of schools in these large-scale medical experiments ebbed and flowed throughout the 1900s—and the practice fizzled out in the latter half of the century.

“[Schools’] social and institutional significance interacted differently with the narratives surrounding each disease, the public’s changing perception of medicine and science and society’s changing values,” Will Schupmann, a sociology Ph.D. candidate at the University of California, Los Angeles, wrote in a 2018 article in the American Journal of Public Health.

Germ theory—the notion that diseases are caused by microorganisms—began gaining traction in the medical community in the mid-to-late 1900s. And schools, where diseases like smallpox and tuberculosis spread easily among children, increasingly played central roles in public health efforts during the Progressive Era.

“Progressive social reformers would come in and teach you everything from how to brush your teeth to how to wash your hands with soap to how to keep a clean household,” says Elena Conis, professor of journalism and history at the University of California, Berkeley and author of Vaccine Nation: America's Changing Relationship with Immunization. “The idea was societal uplift by focusing on the young.”

The United States reported 13,000 to 15,000 diphtheria deaths annually in the 1920s. New York City Board of Health laboratory director William Hallock Park and his team spent years testing a diphtheria vaccine on institutionalized children in hospitals and orphanages. But they needed a larger sample size to prove its efficacy.

“I think the reason in favor of it was, you have here this large population of children that you can follow over time,” says James Colgrove, professor of public health at Columbia University and author of State of Immunity: The Politics of Vaccination in Twentieth-Century America. “And you know where they are, and they are accessible to you.”

Under Park’s leadership, New York City physicians turned to the city’s public schools to test the toxin–antitoxin mixture on more than 50,000 schoolchildren across the city, according to Schupmann. Despite obtaining consent from all their parents, many were skeptical of the state’s vaccination efforts. Principals wrote letters to parents encouraging them to participate, and teachers distributed consent forms to students.

Here’s how the trial worked: Doctors screened half the students for diphtheria immunity with a skin test (called the Schick test). A small amount of diphtheria toxin was injected, and if a red bump appeared, the child didn’t have immunity and got the toxin-antitoxin mixture. The other half of students were neither tested nor given the vaccine. The latter group ultimately developed four times as many cases of diphtheria.

While the vaccine lowered diphtheria cases, its safety was questioned in medical literature, according to the National Vaccine Information Center. It wasn’t until later diphtheria vaccines became routinely available in the 1940s that cases really began to decline.

Polio outbreaks began increasing in the early 20th century and peaked in 1952, with over 21,000 paralytic cases. With its unpredictability and potential for paralysis (or death), polio invoked an unprecedented sense of fear in parents. That’s, in part, because the nonprofit National Foundation for Infantile Paralysis (later renamed the March of Dimes) drew attention to the disease with a major fundraising campaign for the development of a safe, effective vaccine. 

Because the March of Dimes—not scientists—planned to sponsor trials of American virologist Jonas Salk’s vaccine, some state officials wondered if impartial, rigorous testing was truly feasible. Some researchers also questioned the safety and efficacy of Salk’s use of a killed (inactivated) poliovirus on so many kids. 

Still, the trials began on April 26, 1954, at the Franklin Sherman Elementary School in McLean, Virginia, and involved 1.8 million children between 6 and 9 years old across 44 states, plus Finland and Canada. The effort drew unprecedented media coverage, as newspapers published photos of students lining up to get their shot.

Dr. Richard Mulvaney, who administered the first vaccine in the trial to six-year-old Randall Kerr, later recalled, “There were a lot of reporters, TV cameras and kids out in the hall screaming.” In the postwar era of scientific progress, schools touted participation in the vaccine trials as a patriotic or community deed, historians say.

“[Parents] were throwing their kids into line,” says David Oshinsky, professor of medicine at NYU Langone Health and author of Polio: An American Story. “The reason was risk versus reward.”

Schools sent parents “requests to participate” and collaborated with politicians, parent-teacher associations and local health officials to promote the trials, according to Education Week. Schools also held parent information orientations, and the March of Dimes gave kids who participated a printed card, dubbing them “Polio Pioneers.” 

The trial was the first to use the now-standard double-blind method, whereby neither the patient nor the attending doctor knew whether the injection was a vaccine or placebo. It concluded when, on April 12, 1955, Dr. Thomas Francis Jr. of the University of Michigan, publicly announced the Salk vaccine was up to 90 percent effective in preventing paralytic cases of the disease.

Before the United States launched its measles vaccination program in 1963, likely 3 to 4 million people caught the illness annually in the 1950s, according to the CDC. But on average, only 549,000 annual cases were reported, as were nearly 500 measles deaths.

In the late 1950s and early 1960s, researchers held measles vaccine trials at schools nationwide, after testing on institutionalized populations, according to Schupmann. Researchers also turned to other trial sites, including hospitals and medical clinics.

Like with polio, the medical community framed participation in the trials as a community event. However, the measles vaccine trials were much smaller and received much less publicity.

Amid the rise of the counterculture movement, decreasing post-war patriotic fervor and a lack of urgency around measles compared with polio and diphtheria, perceptions about using schools for medical experiments began to shift. Colgrove points to “a combination of some methodological and practical issues, and then some degree of concern about the ethics of those trials,” especially since they involved children.

“On the one hand, you have this huge benefit, that it’s a huge pool of children that you can follow over time," Colgrove says. "On the other hand, it’s complicated to work in schools.”