John Franklin Enders

The American virologist John Franklin Enders (1897-1985), a leader in modern virology, cultivated polio-virus in tissue cultures of human cells and developed an attenuated live vaccine for measles.

John Franklin Enders was born on Feb. 10, 1897, in West Hartford, Conn. After serving from 1917 to 1920 in the United States Naval Reserve Flying Corps, he achieved his undergraduate degree at Yale University. In 1922, he earned a master's degree in English at Harvard University. But before completing doctoral work he became attracted to the study of bacteriology under Hans Zinsser, with whom he developed methods of synthesizing anti-typhus vaccines. He was married to Sarah Bennett in 1927, with whom he had two children; she died in 1943. In 1930 he received his doctorate in microbiology. He then embarked upon a remarkable and productive career as a member of the faculty of Harvard Medical School. During World War II, he was a civilian consultant on epidemic diseases to the Secretary of War, and after 1945 was affiliated with the Civilian Commission on Virus and Rickettsial Disease until 1949. He became head of the Research Division of Infectious Diseases of Children's Hospital, Boston, in 1947. In 1951 he married again, this time to Carolyn Keane.

In the late 1930s Enders focused on virologic problems. His first major breakthrough was the development of techniques for detection of antibodies to mumps virus; he and others subsequently showed that the virus could be grown in chick embryos and tissue culture. On the basis of this work the immunology and epidemiology of mumps infection could be studied, a skin test was developed, and it was shown that the infection frequently was inapparent. Finally, the studies provided the basis for the development of preventive measures against the disease, which now include an attenuated live-virus vaccine.

While Enders and his colleagues, Dr. Frederick Robbins and Dr. Thomas Weller, were continuing the study of mumps and chicken-pox viruses, various types of human cells in culture were being used. Enders suggested that some of the cultures be inoculated with poliovirus, which at that time could be studied only with difficulty in a few species of expensive experimental animals. The poliovirus did propagate in one type of culture made up of cells which were not from the nervous system. This discovery, and the studies which it made possible, opened the way to a new era in poliovirus research, the most dramatic aspect of which was the possibility for development of poliovirus vaccines. For this work Enders, Robbins, and Weller were awarded the Nobel Prize in 1954. From the Enders-Robbins-Weller technique, Dr. Jonas Salk was able to produce the first polio vaccine in 1953.

Enders began studies with another disease, measles. In 1954 he reported success in growing the virus in tissue culture and followed this by a model series of investigations that resulted in a measles vaccine in 1962. Turning his concern to cancer-related viruses in later years, he made important contributions to this field, particularly to studies of fusion of cells from different species as a means of altering cell susceptibility to viruses.

His significant contributions to many areas of virology brought him honors from all over the world, including the Presidential Medal of Freedom in 1963, but Enders continued to devote himself to his laboratory and his students. Because of the breadth and incisiveness of his thought, many of his contributions were conceptual and definitive, representing major steps opening up whole new areas for further experimentation and extension of knowledge. Enders wrote close to 200 published papers between 1929 and 1970. In 1939 he co-authored Immunity, Principles and Application in Medicine and Public Health. But, while achieving wide recognition and public acclaim, Enders remained a "virologists' virologist." Towards the end of his life, he sought to apply his knowledge of immunology to the fight against AIDS, especially in trying to halt the progress of the disease during its incubation period in the human body. He died September 8, 1985, of heart failure, while at his home in Waterford, Connecticut.

Further Reading

A tribute to Enders can be found in the foreword to Perspectives in Virology VI (1968), which was dedicated to him. The foreword was written by Frederick C. Robbins, one of Enders's colleagues, with whom he shared the Nobel Prize. Theodore L. Sourkes, Nobel Prize Winners in Medicine and Physiology, 1901-1965 (1953; rev. ed. 1967), includes a biography of Enders and a description of his work. A biography is also in the Nobel Foundation, Physiology or Medicine: Nobel Lectures, Including Presentation Speeches and Laureates' Biographies (3 vols., 1964-1967). Information on his work is in any review of the literature of medical virology and in virology textbooks. □

ENDERS, DR. JOHN FRANKLIN 1897-1985

Dean of the american-virus hunters"; developed procedure for mass production of polio virus; developed vaccine against measles

Delivery of Polio Vaccine

Dr. John Franklin Enders made important contributions in the 1950s to the fight against several infectious diseases, most notably polio. The development of the Salk vaccine in the first half of the decade was a major step in controlling the disease, but even this first major victory was only half-won. The problem of immunizing American children on a wide scale still remained. Large quantities of the polio virus were necessary to make the vaccine, which injected dead viruses into the body in order to stimulate the body's immune system, (See the section on polio in this chapter.)

Nobel Prize

At this time Enders was a professor of microbiology at Harvard Medical School and a director of research at the Children's Medical Center in Boston. His own research into polio determined that the virus could be cultivated in a variety of types of tissue. This discovery made possible mass production of the Salk vaccine. For his achievement Enders was honored by the medical community with several awards, including the 1954 Nobel Prize in medicine, which he shared with two colleagues (and former students), Drs. Thomas Weiler and Frederick Robbins.

Measles Vaccine

Enders's work on viruses and tissue cultures made viral research cheaper and simpler, so that more laboratories and hospitals were able to isolate and identify viruses. Enders used his techniques to isolate the virus that causes measles in 1956, and two years later he developed a live-virus measles vaccine by cultivating the virus in a tissue sample, then isolating it and recultivating it in another sample. After seventy passes, the virus was sufficiently attenuated (weakened) for use in vaccines. The vaccine was tested over a period of several years, during which it often provoked reactions nearly as severe as an actual case of the measles. Researchers eventually determined that the vaccine worked best in conjunction with a dead-virus vaccine or an injection of gamma globulin.

Source:

William Greer, Virus Hunters (New York: Knopf, 1959).