Utilizing the then new techniques of ultra-centrifugation and chemical fractionation, Smadel made significant contributions to the understanding of myxomatosis, viral encephalitis, variola, vaccinia, and psittacosis.
The freshly commissioned Captain Smadel was assigned as Chief Virologist with the First Medical General Laboratory in the European Theater with the mission of controlling the outbreak of typhus fever in the Mediterranean region in May 1943.
Following the Allied victory in Europe, Lieutenant Colonel Smadel became the director of the Department Of Virus and Rickettsial Diseases with at the WRAIR, a position he held after his return to civilian life.
Perhaps Smadel's most notable professional achievement was the series of field studies in Kuala Lumpur in 1948 which established chloramphenicol as an effective treatment for typhus and typhoid fever.
Smadel after exerting much pressure on Jonas Salk and Basil O'Connor was in early 1954 given the assignment of writing the production protocols for the Polio Vaccine.