What's Happening?
The WHO South-East Asia Regional Immunization Technical Advisory Group (SEAR ITAG) is currently reviewing progress and priorities for protecting populations from vaccine-preventable diseases. Despite achieving the highest childhood immunization coverage
levels globally in 2025, with 94% coverage for the third dose of the routine vaccine against diphtheria, tetanus, and pertussis, the region continues to experience multiple measles and other disease outbreaks. These outbreaks are linked to persistent immunity gaps, particularly among older children and adolescents. The number of zero-dose children in the region has substantially declined by 65% since 2021, and the number of un- and under-vaccinated children decreased from an estimated 4.5 million in 2019 to 2 million in 2025. However, these gaps in vaccination coverage persist across and within countries, creating pockets of susceptible populations. Measles remains a significant concern, with immunity gaps driving current transmission and outbreaks. Only four of the ten Member States in the region have achieved measles elimination, falling behind the elimination trajectory.
Why It's Important?
The persistence of immunity gaps in the WHO South-East Asia Region, despite high overall vaccination coverage, highlights a critical challenge in global public health. Measles, a highly contagious disease, can lead to severe complications and even death, especially in vulnerable populations. The failure to achieve measles elimination in most of the region's Member States indicates that localized and targeted efforts are necessary to reach hard-to-reach communities where these gaps are most prevalent. The focus on older children and adolescents as drivers of current measles transmission suggests that vaccination strategies need to extend beyond early childhood to ensure sustained population immunity. This situation underscores the importance of continuous monitoring, timely use of local data, and rigorous program review to identify and address these specific immunity gaps. The economic and social burden of preventable disease outbreaks can be substantial, affecting healthcare systems and community well-being.
What's Next?
SEAR ITAG is reviewing progress across the three impact goals of the Regional Vaccine Implementation Plan (RVIP) 2022–2026, which include increasing equitable access to vaccines, pursuing control and elimination of vaccine-preventable diseases, and reducing mortality and morbidity. The meeting will also examine vaccination across the life-course, including adolescent vaccination and human papillomavirus (HPV) vaccination, which had only 7% coverage in 2025 with an aspiration to reach 48% in 2026. Experts will further review the prioritization and introduction of new and under-utilized vaccines, such as typhoid conjugate, pneumococcal conjugate, and rotavirus vaccines. Discussions will also cover sustainable immunization financing, workforce capacity, surveillance and laboratory systems, immunization information systems, vaccine hesitancy, misinformation, and the implications of climate change, urbanization, migration, and humanitarian emergencies for immunization programs. The expert group will provide guidance for the next Regional Vaccine Implementation Plan beyond 2026, focusing on accelerating measles and rubella elimination, reducing future outbreak risks, strengthening domestic financing and partnerships, and sustaining effective surveillance.
Beyond the Headlines
The ongoing challenges in the WHO South-East Asia Region underscore a broader global issue: achieving high overall vaccination rates does not automatically guarantee the elimination of vaccine-preventable diseases. The concept of 'immunity gaps' points to the complex interplay of factors beyond simple coverage numbers, including subnational disparities, access issues in hard-to-reach communities, and vaccine hesitancy among specific age groups. The emphasis on older children and adolescents suggests a need for evolving public health strategies that consider the entire life-course for vaccination, moving beyond traditional childhood immunization schedules. Furthermore, the discussion around vaccine hesitancy and misinformation highlights the critical role of public trust and effective communication in maintaining high vaccination rates. The implications of climate change, urbanization, migration, and humanitarian emergencies on immunization programs also signal the increasing complexity of public health in a rapidly changing world, requiring adaptable and resilient vaccination strategies.
