The research Dr. Yvonne Maldonado has conducted has been focused on epidemiologic aspects of viral vaccine development and prevention of perinatal HIV transmission. A major project has been to identify the molecular epidemiology of factors affecting the immunogenicity of oral polio vaccine (OPV) among children living in developing areas of the world, where OPV immunogenicity is poor. Dr. Maldonando's group has identified several factors which affect the poor immunogenicity of OPV and will conduct clinical studies to attempt to improve immunogenicity.