Largest catch-up initiative delivers over 100 million childhood vaccinations

WHO, UNICEF and Gavi say The Big Catch-Up has delivered more than 100 million childhood vaccine doses across 36 countries.

The joint announcement came on April 24, 2026, at the start of World Immunization Week. The agencies said the campaign reached an estimated 18.3 million children, including about 12.3 million zero-dose children and roughly 15 million who had never received a measles vaccine.

The initiative concluded in March 2026, but the agencies said it is on track to meet its target of reaching 21 million children.

The campaign was launched in 2023 to help recover immunization coverage that had fallen behind in many countries. WHO, UNICEF and Gavi said the effort was aimed at closing immunity gaps and restoring routine vaccination after years of disruption.

The agencies’ final figures will likely be followed by country-by-country breakdowns and later health-system analysis, but the headline milestone is now clear: more than 100 million doses have been delivered.