He served as "penicillin czar" during World War II, responsible for managing distribution and allocation of the then-new drug for civilian uses in the United States, and was dean of the Boston University School of Medicine.
Keefer taught at Johns Hopkins, the University of Chicago, and Peking Union Medical College (then spelled Peiping Union Medical College) in Beijing, China, before spending 10 years at Harvard University's Thorndike Memorial Laboratory, at Boston City Hospital.
[5] In July 1943, facing shortages of the newly developed antibiotic penicillin, the U.S. War Production Board put Dr. Keefer in charge of domestic supplies and distribution of the drug, which was reserved primarily for military use.
For eight months he served as "penicillin czar", responsible for rationing civilian use and monitoring clinical reports in order to compile a fuller picture of the uses and limitations of the new drug.
[6][7] In this role, he personally reviewed all potential civilian cases, making the determination of which individuals would receive the drug and which would not.