Pittman completed her Ph.D. dissertation work on the pathogenesis of pneumococcus pneumonia after taking a job in 1928 at the Rockefeller Institute in New York to work with Dr. Rufus Cole on the question, “Does Hemophilus influenza cause influenza?,” one of the perplexing medical problems of that time. Her work on this question led to her discovery that a second (later found to be multiple) strains of the organism existed, some that were encapsulated. This research permitted the development of an antiserum and later a vaccine known as Hib against the meningitis caused by one strain (known as the b strain) of H. influenza, which often resulted in blindness and sometimes death in younger children.