On Feb. 23 1945, Karl Habel, chief, Laboratory of Biology of. Viruses, National Institute of Allergy and Infectious Diseases, reported in Public Health Report  that he had cultivated mumps virus in embryonated eggs and devised serological tests for its presence.

The applicability of this egg virus to complement fixation, virus neutralization, and skin tests opens the way for a practical approach to the study of the epidemiology of mumps in military forces.

Habel spent nearly 30 years at the National Institutes of Health (NIH), where he studied virus diseases and established himself as a world-renowned expert on rabies.