11/24/2025
She proved in 1944 that a killed-virus polio vaccine could work. Then she left science to raise her family. Jonas Salk used her method, became famous. History forgot her.
Everyone knows Jonas Salk. His name is in history books, on buildings, in the stories parents tell about the day polio was conquered.
Almost no one knows Isabel Morgan.
In the 1940s, polio was every parent's nightmare. The disease struck without warning, mostly in summer, mostly targeting children. A child could be playing outside one day and paralyzed the next, trapped in an iron lung, their small body encased in a massive metal cylinder that breathed for them.
Public pools closed. Movie theaters emptied. Parents lived in terror every summer, watching for the first signs—fever, stiff neck, muscle weakness.
Scientists around the world were racing for a vaccine. But there was a problem: Everyone believed they knew the only way to do it.
The scientific consensus was clear: Only a live-virus vaccine would work. You had to use a weakened but still-living version of the virus to create immunity. Anything else—especially a killed-virus vaccine—was considered impossible, a waste of time, scientifically unsound.
Dr. Isabel Morgan disagreed.
She was working at Johns Hopkins University in the early 1940s, studying poliovirus in her laboratory. She was the daughter of Thomas Hunt Morgan, a Nobel Prize-winning geneticist, so she'd grown up around groundbreaking science. But she wasn't riding on her father's reputation—she was brilliant in her own right.
And she had a theory that went against everything the field believed.
What if you could kill the virus—completely inactivate it—but keep its structure intact enough that the immune system would still recognize it and build defenses? What if a killed-virus vaccine could work?
Her colleagues were skeptical. The leading virologists of the era dismissed the idea. Live-virus vaccines were the future, they insisted.
Isabel Morgan went to work anyway.
She used formaldehyde to inactivate poliovirus samples, then tested them on monkeys and chimpanzees. It was meticulous, painstaking work. Each experiment had to be perfect because she was challenging fundamental assumptions about how vaccines worked.
And then, in 1944, she proved it.
She published findings showing that her killed-virus vaccine successfully protected primates from polio infection. For the first time in history, someone had demonstrated that you didn't need a live virus to create immunity.
It was revolutionary. It opened an entirely new pathway toward a human vaccine—one that would be safer, with no risk of the vaccine itself causing the disease.
Dr. Isabel Morgan was on the verge of medical history. The next logical step was human trials. She had the methodology, the proof of concept, the momentum.
And then, in 1949, she left.
She resigned from Johns Hopkins, married a former colleague named David Mountain, and moved to Westchester County, New York. She dedicated herself to raising a family, including a stepson with severe learning disabilities who needed significant care.
She walked away from the research that could have made her one of the most famous scientists in the world.
We can't know all her reasons. Maybe she wanted a family more than fame. Maybe the pressure of being a woman in a male-dominated field was exhausting. Maybe she saw the intensive care her stepson needed and chose to provide it.
Maybe it was all of those things.
What we do know is that this was a choice countless brilliant women have faced: Continue pushing forward in a demanding career where you're constantly having to prove yourself, or step back toward family and the private sphere where society says you belong.
Isabel Morgan chose family.
And Jonas Salk chose her research.
A few years after Morgan left, a young researcher at the University of Pittsburgh named Jonas Salk picked up where she'd left off. He used her killed-virus approach. He refined her formaldehyde-inactivation method. He built directly on the foundation she'd laid.
In 1954, massive human trials began. On April 12, 1955, the results were announced: The Salk vaccine was safe and effective.
Church bells rang across America. It was declared a miracle. Jonas Salk became one of the most famous men in the world. When asked who owned the patent, he famously replied, "The people, I would say. There is no patent. Could you patent the sun?"
It was a beautiful sentiment. He refused to profit from the vaccine, ensuring it could be distributed widely.
But here's what didn't make headlines: The entire approach—the killed-virus methodology that made the vaccine possible—came from Isabel Morgan.
Virologist Maurice Hilleman would later say bluntly: "It was Isabel Morgan's vaccine."
But the world called it the Salk vaccine. Only Jonas Salk's name went into the history books. Only Jonas Salk got ticker-tape parades and appeared on the cover of TIME magazine.
Isabel Morgan stayed home in Westchester County, raising her family, and watched someone else get credit for proving her theory worked.
To be clear: Jonas Salk did important work. He moved the research forward, conducted the human trials, oversaw the massive rollout. His contributions were real.
But they were built entirely on Isabel Morgan's breakthrough.
She was the one who challenged scientific dogma. She was the one who proved everyone wrong about killed-virus vaccines. She was the one who opened the path.
And history forgot her.
Isabel Morgan lived until 1996. She was 84 years old when she died. She did receive some recognition later in life—she was elected to the National Academy of Sciences, and some scientists acknowledged her contributions.
But ask anyone on the street about the polio vaccine, and they'll say "Jonas Salk."
Ask them about Isabel Morgan, and you'll get blank stares.
This is the pattern we see over and over in science: A woman does groundbreaking work. A man builds on it, gets the credit, becomes famous. The woman becomes a footnote, if she's mentioned at all.
Rosalind Franklin and DNA. Lise Meitner and nuclear fission. Jocelyn Bell Burnell and pulsars. And Isabel Morgan and the polio vaccine.
We don't know what would have happened if Isabel Morgan had stayed in research. Maybe she would have led the human trials herself. Maybe her name would be the one everyone knows.
Or maybe, as a woman in 1950s science, she would have been pushed aside anyway. Maybe a man would have taken over the project regardless. Maybe she saw that reality and decided family was a better use of her brilliance than fighting for recognition she'd never receive.
We can't rewrite history. We can't know what she was thinking.
But we can do this: We can remember her name.
We can tell the truth about who proved the killed-virus polio vaccine would work.
We can acknowledge that the vaccine that saved millions of children built on a foundation laid by Dr. Isabel Morgan.
Jonas Salk became famous for conquering polio.
Isabel Morgan made conquering polio possible.
In 1944, she proved everyone wrong about how vaccines could work.
In 1949, she walked away from the glory.
In 1955, someone else got the parade.
And for decades, history didn't even mention her name.
But it should have. It should have from the beginning.
Dr. Isabel Morgan. The woman who opened the path to the polio vaccine.
Remember her.
