Immunizations and vaccines: a decade of successes and reversals, and a call for 'vaccine diplomacy'.

Over the last decade we have seen extraordinary public health gains due to expansions in global vaccination programs led by United Nations (UN) agencies, including Gavi, the Vaccine Alliance, UNICEF and the WHO. These initiatives have reduced childhood deaths from measles, tetanus and other vaccine-preventable diseases by almost one half. There is additional excitement over the potential development and introduction of new vaccines to prevent highly lethal respiratory virus infections, as well as tuberculosis, malaria, HIV/AIDS and several neglected tropical diseases. However, these successes are under threat due to political instability, conflict and an accelerating antivaccine movement. New initiatives in vaccine diplomacy will be required to combat these challenges.