Vaccination remains one of the most effective public health interventions to prevent infectious diseases. This book outlines the science, policy, and logistics behind immunization programs. Topics include vaccine development, safety monitoring, program delivery, and community outreach. It also discusses vaccine hesitancy, equity in access, and global immunization strategies. Special attention is given to routine childhood schedules, emergency responses, and the role of international partnerships.
Gisela Keller is an immunologist and public health advisor whose research investigates vaccine efficacy, coverage disparities, and community-based immunization models. She has supported national and regional vaccination strategies, including outbreak response planning. Gisela’s fieldwork spans several continents, with a particular focus on rural and low-access populations. Her publications address topics such as vaccine confidence, cold-chain logistics, and public awareness campaigns. She is actively involved in training immunization program staff and evaluating policy outcomes.