The swift development of effective vaccines against COVID-19 was an unprecedented scientific achievement. But production challenges, vaccine nationalism, and new variants have all presented hurdles.

The world is inching closer to eradicating polio, but armed conflicts and opposition to vaccines stand in the way of finally eliminating the disease.

Since its postwar founding, the UN agency has garnered both praise and criticism for its response to international public health crises, including the COVID-19 pandemic.

A leading killer among diseases is now targeted for eradication by the middle of this century. Efforts to combat malaria are costly and challenging.