Combating vaccine hesitancy and other 21st century social determinants in the global fight against measles.

The year 2019 marked the return of measles after almost two decades of unprecedented successes in global vaccination programs. Measles transmission due to sharp declines in measles-mumps-rubella (MMR) vaccination coverage is now widespread among nations that previously saw impressive public health gains including Philippines, DR Congo, Madagascar, Samoa, many in Europe, and the United States and Venezuela in the Americas. Key determinants include the interruption of vaccine health systems due to war, conflict, and political instability; food insecurity and urbanization; and an increasingly globalized vaccine hesitancy or antivaccine movement. Vaccine hesitancy is partly responsible for over 100000 measles cases in Europe in 2019, and the re-emergence of measles to the United States almost twenty years after it was eliminated. Three major elements currently comprise the American antivaccine movement, including a media empire, a political arm, and deliberate predatory behavior. New strategies will be required to counter these activities.