Immunization efforts are under growing threat as misinformation, population growth, humanitarian crises and funding cuts jeopardize progress and leave millions of children, adolescents and adults at risk, warn WHO, UNICEF, and Gavi during World Immunization Week, 24–30 April.

Outbreaks of vaccine-preventable diseases such as measles, meningitis and yellow fever are rising globally, and diseases like diphtheria, that have long been held at bay or virtually disappeared in many countries, are at risk of re-emerging. In response, the agencies are calling for urgent and sustained political attention and investment to strengthen immunization programmes and protect significant progress achieved in reducing child mortality over the past 50 years.