Katz became a staff member at Children's Hospital working with
Nobel Laureate John F. Enders. He remained with Enders for 12 years during which time they developed the attenuated
measles vaccine now used throughout the world. In addition to his work on measles, Katz had been involved in studies of many other pathogens and infectious diseases including
vaccinia, polio, rubella, influenza, pertussis, HIV, and
Haemophilus influenzae b conjugates. Katz chaired the Committee on Infectious Diseases of the
American Academy of Pediatrics (the Redbook Committee), the
Advisory Committee on Immunization Practices (ACIP) of the
Centers for Disease Control, the Vaccine Priorities Study of the
Institute of Medicine (IOM), and several WHO and CVI vaccine and HIV panels. He was a member of many scientific advisory committees and boards including the NIH, IOM, WHO, St. Jude Children's Research Hospital, The Burroughs Wellcome Fund (Chairman), and the Hasbro Children's Foundation. He was chairman of the Public Policy Council of the Infectious Diseases Society of America (IDSA) and co-chaired IDSA's Vaccine Initiative. ==Awards and honors==