Kate O’Brien, MD, MPH, is Director of the Immunization, Vaccines and Biologicals Department at the World Health Organization. In this role she is responsible for leading the overall work and strategy of the Department to  advance the vision of a world where everyone, everywhere, at every age, fully benefits from vaccines for good  health and wellbeing. The Department works across all levels of WHO (country, region and headquarters) in  collaboration with partners to deliver country impact.  

Prior to joining WHO she was Professor of International Health and Epidemiology and Executive Director of the  International Vaccine Access Center at the Johns Hopkins Bloomberg School of Public Health. Her research and  policy work focused on vaccine preventable illnesses, especially for pneumonia causing pathogens including  pneumococcal disease; Haemophilus influenzae type b; respiratory syncytial virus and influenza. Most recently  she led the PERCH multi-site study of pneumonia etiology in hospitalized children in Asia and Africa.