Dorothy Millicent Horstmann | Biography

Dorothy Millicent Horstmann played a significant yet often unacknowledged role in the development of the polio vaccine . In the late 1940s and early 1950s, before polio immunizations were considered feasible, she conducted groundbreaking animal studies which proved that the polio virus reaches the nervous system through the bloodstream. In 1952, while working at the Yale School of Medicine, she set up an experiment to determine whether polio first appeared in the blood before moving on to the brain. She fed monkeys and chimpanzees small quantities of polio virus , then examined the blood for traces of the it. The animals did not immediately develop symptoms of polio, yet small traces of virus were observable in their blood. Many of the animals later developed paralysis, one of polio's debilitating symptoms.

Horstmann was born July 2, 1911, in Spokane, Washington, to Henry and Anna (Humold) Horstmann. She received her B.A. in 1936 and her M.D. in 1940 from the University of California. After holding an internship at the San Francisco City and County Hospital from 1939 to 1940, she did her medical residency at Vanderbilt University. In 1942, she began her long affiliation with the Yale University School of Medicine. In 1945, Horstmann was appointed associate professor of medicine at Yale; from 1947 to 1948, she held a National Institutes of Health postdoctoral research fellowship there. In 1961, Horstmann rose to professor of epidemiology and pediatrics, and in 1969 she was named John Rodman Paul Professor of Epidemiology and Pediatrics. Since 1982, she has held the titles of emeritus professor and senior research scientist at Yale. Horstmann was led to her experiments by the work of William McDowell Hammon, who showed that injections of gamma globulin, an antibody-rich serum extracted from plasma, could produce temporary immunity to polio. From this lead, Horstmann hypothesized that the polio virus first travelled through the bloodstream before finally settling in the nervous system. The discoveries she made during her experiments with monkeys and chimpanzees were initially dismissed by some virologists as inconclusive, because in most patients who had developed polio, no virus had been found in their blood. It was subsequently established, however, that by the time the symptoms of polio became clinically evident, the virus had already left the bloodstream and established itself in the nervous system. Horstmann's work and the parallel studies of David Bodian at Johns Hopkins University proved that polio is an intestinal infection which can enter the nervous system through the bloodstream.

Throughout the 1950s and 1960s, Horstmann participated in field trials to establish the effectiveness and safety of polio vaccines. During her distinguished career, Horstmann also studied maternal rubella and the rubella syndrome in infants. She holds four honorary doctorates and has received numerous honors and awards, including the James D. Bruce Award of the American College of Physicians, 1975, Denmark's Thorvold Madsen Award, 1977, and the Maxwell Finland Award of the Infectious Diseases Society of America, 1978. She is a member of the National Academy of Sciences, the American Society of Clinical Investigations, the American College of Physicians, and the Royal Society of Medicine.