Maurice Hilleman: Vaccine Pioneer and Lifesaver

Some say that Maurice Hilleman is the father of mankind. They call him this because, thanks to his work, the life expectancy of all humans has increased. However, amazingly, his name isn't very well-known.
Maurice Hilleman: Vaccine Pioneer and Lifesaver

Last update: 08 November, 2022

Most of us are alive today thanks to Maurice Hilleman, even though we might not know it. As a matter of fact, no other scientist has contributed to life expectancy in the way this microbiologist from such humble beginnings did.

Hilleman developed vaccines against mumps, measles, pneumonia, chickenpox, and hepatitis B. In fact, in total, he developed vaccines against 40 diseases. Nobody else has a record like this. However, even today, in the information age, his name remains largely unknown.

“I think vaccines should be considered the technological opportunity of the 20th century.”

-Maurice Hilleman-

Everyone in the world who has access to medical services today is given vaccines from birth. Maurice Hilleman developed a large number of them. Those who knew him said he was a grumpy old man who could be lively and funny as well. Nevertheless, more importantly, he was an incredibly committed and dedicated man.

A little girl having a vaccination.

The early years of Maurice Hilleman

Maurice Hilleman was born in Montana on August 30, 1919. His mother and twin sister both died in childbirth. He ended up being the youngest of eight siblings in a humble farming family. They all worked on their farm to survive.

Maurice, like his brothers, worked on the farm. He was particularly involved with taking care of the chickens. In fact, years later, he said that this work helped him greatly. This was because many of his vaccines were egg-based.

His family was Lutheran. Consequently, he caused a bit of a scandal when he was caught reading Darwin’s On the Origin of Species. This book was banned because it was considered only suitable for atheists. However, Maurice’s older brother didn’t see this as a negative event, but a beacon of hope instead. For this reason, he helped and encouraged Maurice to go to college.

Maurice Hilleman: a genius in the making

Maurice Hilleman was a good student. He always achieved excellent grades. As a result, he earned a scholarship to obtain his doctorate at the University of Chicago. There, he graduated in microbiology in 1941.

He began to earn recognition when he developed a Japanese encephalitis vaccine in World War II. This was to vaccinate soldiers in the Pacific who’d been afflicted with this disease. Later, he went to work at an army research center. There, he made another groundbreaking discovery.

He and a colleague detected a new strain of flu that had broken out in Hong Kong. Thanks to one of his discoveries, “antigenic drift”, he managed to design a vaccine to ward off the virus. In fact, this outbreak could have become a pandemic but it was brought under control thanks to Hilleman. Even so, more than 69,000 Americans died from this illness.

Hilleman’s devotion to Merck

In 1957, Hilleman began working with the pharmaceutical company, Merck. Many believe that the reason he didn’t achieve more recognition in his life was due to his links with this company. Nonetheless, Hilleman did develop most of his vaccines while working for this company.

One of his most important vaccines was against mumps. There’s an interesting story behind its development. Hilleman married a nurse and had two daughters. The eldest, Jeryl Lynn, fell ill with mumps at the age of five. Hilleman took a sample for cultivation and thanks to this, he developed the mumps vaccine, which most of us are now given in childhood.

Maurice Hilleman was scrupulous in his work. In fact, he personally supervised and controlled every stage in the development of each new vaccine. Perhaps this was why he had the reputation of being demanding, prickly, and narcissistic.

A medic holding a vaccine.

The recognition that never came

They say Maurice Hilleman was especially proud of his hepatitis B vaccine. The vaccine is estimated to have reduced deaths from this disease by 95%, at least in the United States. In addition, people use the vaccine in 150 other countries.

This vaccine was also the first to prevent cancer in humans, more particularly liver cancer. However, Maurice Hilleman’s dream was to develop a vaccine against any kind of viral cancer. Experts say he did it, in part, when he developed the vaccine against Marek’s disease.

His prestige in the field of science is undeniable. Furthermore, he held various positions and was even an advisor to the World Health Organization. However, despite this impressive record, he never achieved worldwide fame.

Hilleman had to leave Merck due to forced retirement. Nevertheless, he continued to work on his vaccines until he died at the age of 85 in 2005. He was survived by his wife, two daughters, and five grandchildren.


All cited sources were thoroughly reviewed by our team to ensure their quality, reliability, currency, and validity. The bibliography of this article was considered reliable and of academic or scientific accuracy.


  • Tuells, J. (2010). Maurice Hilleman (1919-2005), el hombre que inventaba vacunas. Vacunas, 11(1), 37-43.

This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.