Dr. Ogra’s career in medicine began in the early 1960's. His academic leadership has focused on research, teaching and patient care in childhood infections, mucosal vaccine development, and definition of biologic markers of immunity against human infections. His major scientific contributions began with the first functional characterization of secretory IgA and “alimentary” mucosal immunity in natural or vaccine induced infection with poliovirus. In subsequent investigations, he defined the role of secretory IgA and cellular mucosal immune responses to such human infections as rubella, mumps, hepatitis B virus and enteroviruses. His laboratory providedan extensive immunologic characterization of human milk, its role in maternal-neonatal interactions and childhood infections, and the association of mammary glands with other components of the common mucosal immune system. Other investigations from his laboratory identified important components of host-pathogen interactions underlying the pathogenesis of mucosal infections, notably in Bronchiolitis due to the respiratory syncytial virus (RSV), gastroenteritis due to rotavirus, and immunologic aspects of Otitis media in childhood.