How a New Vaccine Was Developed in Record Time in the 1960s

The invention of the modern mumps vaccine is legendary in medical textbooks. In 1963, a star researcher from the pharmaceutical company Merck took a sample from his own daughter’s throat to start growing a weakened form of the mumps virus. And only four years later, in record time, Merck authorized Mumpsvax as the world’s first effective vaccine against this common and contagious childhood illness.

But a closer look at the history of vaccines shows that this popular story overlooks the decades-long search for a cure for mumps that began in earnest during World War II. And this overshadows the fact that in the 1940s and 1950s, researchers looking for polio and measles vaccines made progressive breakthroughs in laboratory techniques that ultimately made the rapid development of the Mumpsvax of the 1960s possible.

The “Jeryl Lynn” strain

Dr maurice hilleman

Dr Maurice Hilleman, circa 1958.

The National Library of Medicine

At 1:00 a.m. on March 21, 1963, a five-year-old girl in Philadelphia woke up her father, Dr. Maurice Hilleman, complaining of a sore throat. Hilleman, a thorny genius working at Merck, immediately diagnosed her with a case of mumps, a generally harmless childhood illness for which there was no treatment, and sent her back to bed.

But Hilleman couldn’t go back to sleep – he had an idea. Another research laboratory had just approved a measles vaccine based on a new technique for growing weakened forms of a virus living in chicken embryos. Maybe he could do the same for mumps. Hilleman rushed to Merck to sample supplies, came back and dabbed his daughter’s throat, then brought the viral culture back to the laboratory.

The mumps vaccine that Hilleman developed in 1967 from this nocturnal inspiration is still used as part of the combined measles, mumps and rubella (MMR) vaccine given to infants around the world. In the United States alone, mumps infected 186,000 children a year in the 1960s. Today, thanks to the vaccine, there are fewer than 1,000 mumps infections per year.

Perhaps the most charming part of Hilleman’s mumps vaccine history is that he named the strain of the mumps virus used to make the vaccine after his young daughter, Jeryl Lynn. The same Jeryl Lynn strain is still used in the production of mumps vaccine today.

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Mumps was a threat to national security during the Second World War

The captivating story of Hilleman’s record development of the mumps vaccine contains all the elements of a mid-century American success story, but the cure for mumps didn’t start that fateful night in 1963.

Since the First World War, the American army has identified mumps as a real problem. Elena Conis is a medical and public health historian at the UC Berkeley Graduate School of Journalism and author of Vaccine Nation: America’s Changing Relationship with Vaccination. She says mumps is the most debilitating in adult men, who often suffer from painful swelling of the testicles.

“When US troops gathered in overcrowded camps and barracks, if there was a case of mumps, you would have the whole camp in the hospital wing for weeks,” said Conis.

During the First World War, mumps was the main cause of missed active duty days for the United States Army in France and reached a total of 230,356 cases. During the Second World War, the threat of mumps and measles was serious enough for the Military Office of Scientific Research and Development to treat it as a national security problem.

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A breakthrough is “hatched”

One of the main barriers to vaccine development is the growth of large quantities of the target virus. In 1945, two American research teams simultaneously discovered that the mumps virus could be cultivated in chicken eggs, in particular “embryonic” eggs which had been fertilized.

Karl Habel of the US Health Service used the egg technique to produce the very first experimental mumps vaccine in 1946. Habel’s vaccine was “inactivated”, which means it contained no live mumps virus , just dead virus particles. The inactive mumps vaccine was tested on 2,825 West Indian workers on a sugar cane plantation in Florida where mumps were rife, and it showed 58% effectiveness against the virus.

The world had their first mumps vaccine, but by that time World War II was over and the urgency to find a cure for mumps had passed.

“In the 1940s, the CDC did not identify mumps among children as a top health priority,” says Conis. “After the war ended, diseases like pneumonia and the flu were a much bigger concern. Parents did not like when their children had mumps, but they were considered part of childhood. ”

WATCH: World War II documentaries on the historic chest

Science improves game against polio and measles

John enders

American physician John Enders, circa 1966.

Pictorial parade / Getty Images

John Enders won a Nobel Prize in 1954 for his work on the cultivation of the polio virus which led to a long-awaited polio vaccine. With Habel, Enders is co-credited with the discovery of the embryonic chicken egg technique for the growth of viruses. And like Habel, Enders first tested for the mumps virus before moving on to polio and finally measles.

The polio vaccine was a game-changer, but it was also based on an inactivated or dead virus. To develop a measles vaccine, Enders understood that if you repeatedly transmit the same virus to a chicken embryo, it weakens over time. The result is an “attenuated” virus, an organism far too weak to cause full-fledged infection in humans, but strong enough to trigger an immune response.

“It was the development of the polio vaccine in the 1950s that advanced the techniques that made possible the development of the measles vaccine and then mumps in the 1960s,” says Conis. “And Hilleman would never have been able to develop the mumps vaccine if Enders had not developed the culture techniques he used.”

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Without MMR, there would be no mumps vaccine

Mmr vaccine

A nurse prepares the measles, mumps and rubella (MMR) vaccine at Rockland County Health Department in Rockland County, New York on April 5, 2019.

Johannes Eisele / AFP / Getty Images

Hilleman deserves considerable credit for a lifetime of groundbreaking work on vaccines. Not only did he create a highly effective mumps vaccine using a live virus, but he improved the Enders measles vaccine and helped develop vaccines against rubella, hepatitis B and a viral form of it. liver cancer.

But when Mumpsvax was licensed in 1967, Conis said there was no market for a mumps vaccine. The public regarded childhood mumps as an annoying disease, the main symptom of which was swelling of the face glands resembling chipmunks. And some pediatricians have found it better to be exposed to mumps and naturally acquire immunity.

Hilleman’s mumps vaccine could have languished if Merck had not combined it later with vaccines against the much more serious childhood diseases of measles and rubella. The combined MMR vaccine was licensed in 1971 and provided a quick and inexpensive way to immunize large sections of the population against multiple contagious childhood diseases at once.

The result was that in 1974, 40% of American children were immunized against mumps as part of the MMR vaccine. And in 1977, the CDC’s Advisory Committee on Immunization Practices decided that, although mumps was still a low-priority disease, its inclusion in the MMR vaccine ensured mumps vaccination for all children over 12 month.

When the CDC recommended a two-dose MMR regimen in 1998, cases of infant mumps dropped to a record low of less than 400 cases per year.

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