Max Theiler working on yellow fever. In 1926, they disproved Hideyo Noguchi's hypothesis that yellow fever was caused by the bacterium "Leptospira icteroides." In 1928, the year after the disease was identified conclusively as a virus, they showed that the African and South American viruses are immunologically identical. (This followed Adrian Stokes' inducing yellow fever in rhesus macaques from India). In the course of this research, Theiler contracted yellow fever, but survived and developed immunity. In 1930, Theiler moved to the Rockefeller Foundation in New York, where he later became director of the Virus Laboratory. He was professor of epidemiology and public
Theiler's disease multiple horses over several months. In the Northern hemisphere it is most common between August to November. It is seen almost exclusively in adult horses, and lactating broodmares given tetanus antitoxin post foaling may be more susceptible. This disease was described in 1919 by Arnold Theiler, a South African veterinary surgeon, after vaccinating horses against African horse sickness using a live virus vaccine and equine antiserum. It was later described in the United States after vaccinating horses for Eastern Equine Encephalitis, again using live virus vaccines and equine-derived antiserum. It has since been reported throughout North America and Europe. Theiler's