Thomas C. Peebles, 89, who isolated the measles virus, setting the stage for development of the vaccine that freed the world from the deadly scourge, died July 8 at his home in Port Charlotte, Fla. The cause of death was not reported.
Dr. Peebles also led a team that showed the tetanus vaccine could be given every decade instead of every year, developed a way to add fluoride to children's vitamins to prevent tooth decay and founded one of the country's first health maintenance organizations.
The measles discovery came in his third year after graduation from medical school while he was working in the Children's Hospital Boston laboratory of Dr. John F. Enders, who won the 1954 Nobel Prize in Physiology or Medicine for isolating the polio virus.
Enders assigned his young protege to investigate the cause of measles, which in the mid-1950s infected nearly every American child before age 15 and killed about 450 each year. When an outbreak occurred at a nearby elementary school, Dr. Peebles collected blood samples and throat swabs from infected children, telling them that they were "standing on the frontiers of science."
Attempting to grow the suspected virus in dishes containing human tissues, Dr. Peebles found suspicious blobs of damaged cells in the culture taken from an 11-year-old named David Edmonston. Nobody else in the lab thought he had found the virus, however, and Enders removed him from the project.