Krause later served as the dean of medicine at Emory University before returning to National Institutes of Health as a senior scientific advisor at the John E. Fogarty International Center.

[2] For two years before graduation, Krause served in the United States Army guarding German prisoners of war at Fort Riley.

At Rockefeller, Krause worked with his role models Oswald Avery and Rebecca Lancefield and became lifelong friends with Purnell W. Choppin and Maclyn McCarty.

He guided the institute through a period of growth to cope with the re-emergence of microbial diseases as health threats and to stimulate research on the complexity of the immune system.

Responding to the emergence of the AIDS epidemic in the early 1980s, Krause organized field studies in Haiti and Zaire in the search for the origins of the virus.