How Rivalry, Philanthropy, and a Million Child Volunteers Conquered America's Most Feared Disease
For mid-20th century America, few things sparked more terror than the arrival of summer. As temperatures rose, swimming pools closed, playgrounds emptied, and parents scanned their children for feverish symptoms. Poliomyelitis—polio—had arrived. Though statistically less common than accidents or cancer, its ability to cripple and kill children made it a unique cultural nightmare. David M. Oshinsky's Pulitzer-winning Polio: An American Story chronicles the scientific race against this virus, revealing how ego, ethics, and unprecedented public mobilization converged to create a medical miracle 1 7 .
Polio thrived in modern, hygienic societies. Improved sanitation reduced early childhood exposure, leaving populations vulnerable to severe outbreaks. As Oshinsky notes, polio was "never the raging epidemic portrayed by the media," but its targeting of children and seasonal unpredictability fueled disproportionate dread. The 1952 epidemic marked a terrifying peak: 57,879 U.S. cases and 3,145 deaths 6 7 .
President Franklin D. Roosevelt's 1921 polio diagnosis transformed the disease into a national cause. In 1938, he founded the National Foundation for Infantile Paralysis (later March of Dimes), revolutionizing medical philanthropy. Instead of courting wealthy donors, it mobilized grassroots giving—collecting dimes from millions. By 1955, it funded 80% of U.S. polio research and patient care 1 .
Proving a vaccine worked required massive, immediate testing. With polio striking seasonally, Salk had one shot to launch a trial before the 1954 "polio season."
Thomas Francis, a University of Michigan epidemiologist, orchestrated two parallel studies across 44 states:
| Year | Paralytic Cases | Deaths |
|---|---|---|
| 1940 | 10,904 | 1,043 |
| 1952 | 21,269 | 3,145 |
| 1955* | 4,247 | 1,043 |
| 1960 | 2,525 | 230 |
| Arm | Participants | Control Method | Key Advantage |
|---|---|---|---|
| Placebo | 750,000 | Saline injections | Eliminated bias |
| Observed | 1,080,000 | Age-matched peers | Faster enrollment |
| Group | Paralytic Polio Cases | Rate per 100,000 |
|---|---|---|
| Vaccinated | 33 | 16 |
| Placebo | 115 | 57 |
On April 12, 1955 (10th anniversary of FDR's death), Francis announced:
Salk treated poliovirus with formaldehyde, destroying its ability to replicate while retaining its "shape" to train immune systems. This method built on his influenza vaccine work 6 .
Until 1949, poliovirus grew only in live monkey brains—slow and unsafe. John Enders, Thomas Weller, and Frederick Robbins won the 1954 Nobel Prize for culturing it in non-neural human tissue, enabling mass production 9 .
The primary "factory" for growing poliovirus. Sabin later used these for his oral vaccine 6 .
| Reagent | Function | Innovator |
|---|---|---|
| Formaldehyde | Virus inactivation | Salk |
| Human tissue cultures | Virus growth medium | Enders/Weller/Robbins |
| Monkey kidney cells | Live-virus production | Sabin |
Weeks after the vaccine's 1955 launch, 260 polio cases emerged from vaccines by Cutter Laboratories. Flawed inactivation left live virus in 120,000 doses. The tragedy halted production but spurred tighter federal regulation, including creation of polio surveillance units 6 .
By 1961, Sabin's oral vaccine (easier to administer, longer-lasting) replaced Salk's in the U.S. Ironically, it relied on Salk's vaccine to suppress outbreaks during testing .
The conquest of polio was more than science—it was a societal wager.
The conquest of polio was more than science—it was a societal wager. Parents volunteered their children, volunteers mobilized by the hundreds of thousands, and rival researchers put aside egos long enough to validate a breakthrough. As Oshinsky writes, it was "the largest clinical trial ever undertaken," a testament to what focused resources and collective will can achieve 3 . In today's era of rapid vaccine development, the polio story remains a blueprint: meticulous science, transparent communication, and an unwavering commitment to the public good.