Reflecting on World Immunization Week, April 21-28, Angeline Nanni, director of market access at Aeras, discusses the “remarkable results” of expanded immunization programs in a guest post on the Global Health Technologies Coalition’s “Breakthroughs” blog. “Immunization has saved the lives of more children than any other medical intervention in the last 50 years. However, one in five children still do not have access to these lifesaving vaccines,” she notes. Nanni discusses the importance of developing tuberculosis and HIV vaccines, writing, “Prevention through vaccination would be the most cost-effective tool to mitigate these global epidemics.” She adds, “Vaccines have made the world a vastly different place by reducing the incidence of disease, providing freedom from worry and fear of the death and disability that they cause. Vaccines hold the key to a healthier and wealthier world for all of us” (4/26).