March 25, 1863 - May 2, 1946
Election Year: 1908
Scientific Discipline: Microbial Biology
Membership Type: Member
Simon Flexner’s groundbreaking research focused on the way viruses and bacterial infections invade and function within hosts. His development of a treatment protocol for meningitis was a major breakthrough, as he determined that antibacterial serum had to be administered directly into the fluid encompassing the brain and spinal column so that it could reach bacteria insulated by the blood–brain barrier. Flexner also conducted studies on poliomyelitis by inoculating monkeys with the virus. He found that the antibodies that formed could be used to counteract the virus, an important step in the development of a vaccine.
Flexner was apprenticed to a druggist and then attended the Louisville College of Pharmacy, where he graduated in 1882. He later earned his MD degree from University of Louisville in 1889 and then studied pathology and bacteriology at the Johns Hopkins Hospital. He served as professor of pathological anatomy at Johns Hopkins University from 1895 to 1898. In 1899 he moved to the University of Pennsylvania and became the professor of pathology. He was appointed the first director of the Rockefeller Institute for Medical Research, serving there from 1901 to 1935.