National Academy of Sciences, Washington, District of Columbia, United States
Kelser was a member of the National Academy of Sciences, to which he was elected in 1948.
American University, Washington, District of Columbia, United States
Kelser pursued graduate studies at American University, earning the Master of Arts degree in 1922 and the Ph.D. in 1923.
Educated in the public schools of Washington, Kelser took a business course in high school and became a messenger for the Bureau of Animal Industry of the Department of Agriculture. Here he came under the friendly and helpful influence of John R. Mohler, chief of the pathological division of the bureau. While working at the bureau, Kelser enrolled in night classes at the School of Veterinary Medicine of George Washington University and received the Doctor of Veterinary Medicine degree in 1914. He also pursued graduate studies at American University, earning the Master of Arts degree in 1922 and the Ph.D. in 1923.
After some brief experience as a commercial bacteriologist, Kelser took the civil service examination and returned to the Bureau of Animal Industry. From 1915 to 1918 he and his colleagues studied anthrax immune serum and improved the vaccine for the disease.
In 1918 Kelser joined the Veterinary Corps of the U.S. Army. He served with distinction in the army for twenty-eight years, achieving the rank of brigadier general. In 1942 he became the first general officer in the corps; and while he was a chief veterinary officer of the army, the number of officers in the corps grew from 126 in 1938 to over 2,200 during World War II.
Kelser’s abilities in research, evident even prior to his military service, led the army to assign him to various laboratories for periods of time sufficiently long to enable him to carry out some highly successful researches. From 1921 to 1925 he was chief of the Veterinary Laboratory Division of the Army Medical School in Washington. During this period he perfected a better test for detecting botulinus toxin in canned foods.
From 1925 to 1928 Kelser served in the Philippine Islands, where he made a major scientific contribution. Cattle plague, or rinderpest, was at the time a serious problem in many parts of the world, and Philippine agriculture was suffering severely from its effects. Kelser developed an effective means of inactivating the virus with chloroform without destroying its immunizing properties. The resulting vaccine led to the eventual control of the disease.
From 1928 to 1933 Kelser again headed the Veterinary Laboratory Division in Washington, where he completed several important studies. The most notable of these was his elucidation of the mechanism of transmission of the virus of equine encephalomyelitis. Kelser, who was among the early virologists in the 1930s, making important studies in virus characteristics and transmission, showed that the agent of equine encephalomyelitis could be passed from guinea pig to guinea pig and from horse to horse by mosquitoes. Kelser also showed that the mosquito acted not merely as a mechanical agent of viral transfer from animal to animal, but served as a necessary incubating host for the virus. The virus multiplied while in the mosquito, thus increasing its infective powers. This finding was of great interest to those trying to understand the nature of virus diseases. It also had a practical application - in mosquito control - in dealing with widespread encephalomyelitis among horses.
Kelser retired from the army in 1946 but continued to advise the Department of Defense on matters of biological warfare. Upon his retirement, he became dean and professor of bacteriology of the School of Veterinary Medicine at the University of Pennsylvania. In the six years before his sudden death from a stroke, he helped to expand and improve the school’s facilities and research activities.
Kelser was a member of many scientific organizations, including the National Academy of Sciences, to which he was elected in 1948.
In 1914 Kelser married Eveline Harriet Davison.