One of his most significant contributions came while he directed the vaccine development division of Merck & Co. Building on the groundbreaking work of John Enders, Hilleman set out to make Ender's measles vaccine suitable for mass distribution. Ender's vaccine had proven to be too potent, often causing serious rashes and fevers in inoculated children. Hilleman faced an additional obstacle: the chicken embryos in which the measles virus was cultured were themselves infected with a potentially dangerous virus. He located a farm in northern California (Kimber Farms) that was raising virus-free chickens, and he soon struck a deal with the fellow-Montanan who ran the operation. "Montana blood runs very thick," Hilleman reflected, "and chicken blood runs even thicker with me." With healthy chickens, Hilleman patiently weakened the measles virus, step by step, until he reached the perfect level of active virus: just strong enough to trigger a response and produce antibodies, but without causing serious side effects. Then, with this accomplished, he could produce a new vaccine with more benefits and fewer drawbacks.

Measles is caused by a virus and is one of the most contagious diseases known. The virus normally grows in the cells lining the back of the throat and those lining the lungs. The first sign of infection is a high fever lasting one to seven days. During this initial stage the patient may develop multiple symptoms, including a runny nose, cough, red and watery eyes, and small white spots inside the cheeks. A rash develops after several days, typically beginning on the face and upper neck, and then spreading to the hands and feet. Poorly nourished children are at an increased risk of contracting a severe case of measles, especially those who have a vitamin A deficiency or whose immune system is compromised. Childhood deaths are usually caused by the complications associated with measles, rather than by the disease itself. The most serious complications include blindness, an infection of the brain and spinal cord (encephalitis), severe diarrhea, ear infections and severe respiratory infections--such as pneumonia, which is the most common cause of death associated with measles. Though over 30 million cases of measles occur worldwide annually, due to widespread use of Hilleman's vaccine, fewer than 100 cases occur in the United States.  Despite the availability of a safe and effective vaccine for the past several decades, measles continues to be a leading cause of death among children in the developing world. It's estimated that 242,000 people, many of them children, died from measles in 2006. But, vaccination has played a major role, with an estimated 478 million children having received the measles vaccine between 2000 and 2006. As a result, there has been a significant reduction in estimated global measles deaths. Overall, global measles mortality decreased by 68% between 2000 and 2006, with the largest decreases occurring in Africa, where measles cases and deaths fell by 91%.

Table of Contents

Key Insight

Key Experiments or Research

Quotes by the Scientist

Quotes About the Scientist

Anecdotes

Fun Trivia About the Science

Personal Information

Scientific Discovery Timeline

Recommended Books About the Science

Books by the Scientist

Books About the Scientist

Offit, Paul A. Vaccinated: One Man's Quest to Defeat the World's Deadliest Diseases. Harper Paperbacks, 2008.

Awards

Major Academic Papers Written by the Scientist

Curriculum Vitae

Sources/References