A Serious Disease.

Measles was considered a routine childhood illness in 1960. Most children contracted the disease; this was considered a good thing because an adult's infection was thought to be much more serious. Many people did not realize how dangerous measles could be for children, though. Of four million cases in America each year, four hundred — mostly children — ended in death. One out of every four thousand children with measles recovered but was mentally retarded. This "simple" childhood illness was not at all simple.

The Enders Vaccine.

In the late 1950s Dr. John Enders isolated the measles virus. In 1961 he and his colleagues at Harvard University introduced a live-virus vaccine. To reduce side effects, which included fever and rashes, the vaccine was injected in a mixture of gamma globulin. Early tests on children showed the vaccine gave nearly 100 percent...