Global Vaccination Catch-Up Initiative Concludes Successfully
The Big Catch-Up (BCU), a landmark multi-year immunization recovery program coordinated by Gavi, WHO, and UNICEF, has completed its mission to address vaccination declines caused by COVID-19 disruptions. Between 2023 and March 2026, the initiative reached an estimated 18.3 million children aged 1-5 years across 36 countries with over 100 million vaccine doses.
Key Public Health Achievements
Immunization Milestones:
- 12.3 million "zero-dose children" (never previously vaccinated) were reached
- 15 million children received their first measles vaccine
- 23 million doses of inactivated polio vaccine (IPV) administered to under/unvaccinated children
- Notable successes: Ethiopia (2.5M zero-dose DTP1), Nigeria (2M zero-dose DTP1), and 12 participating countries reaching 60%+ of zero-dose children under 5
Addressing Global Vaccine Equity
The 36 participating countries—primarily in Africa and Asia—account for 60% of global "zero-dose" children. These populations predominantly live in fragile, conflict-affected, or underserved communities. The initiative pioneered systematic screening and vaccination of older children (ages 1-5) who had previously missed routine infant immunization, establishing lasting systems for identification and monitoring.
Current Global Concerns
Despite BCU's success, significant challenges persist:
- 14.3 million infants under age one globally still miss routine vaccinations annually
- Measles resurgence: ~11 million cases reported in 2024, with countries facing large outbreaks nearly tripling since 2021
- Rising birth cohorts, conflict displacement, funding constraints, and declining vaccine confidence in previously high-coverage areas complicate ongoing efforts
Pharmacist's Note
For international travelers: This initiative underscores critical immunity gaps in endemic disease regions. Travelers to countries with vaccination program challenges—particularly in Africa and Asia—should verify their own vaccination status against diseases like measles, polio, and diphtheria-tetanus-pertussis well before departure. Those visiting areas affected by conflict or fragile health systems should consult travel medicine specialists regarding additional preventive measures. Vaccine preventable disease outbreaks remain genuine risks in underimmunized populations.
Future Direction
Agencies emphasize that while catch-up campaigns address accumulated deficits, routine immunization programs remain the most sustainable approach. The focus now centers on strengthening domestic health system investments in immunization infrastructure, particularly in conflict-affected regions and vulnerable communities. This aligns with WHO's Immunisation Agenda 2030 priorities and Gavi's 2026-2030 strategic framework.