Gendered Pathways to Missed and Zero-Dose Polio Vaccination in Children: A Narrative Review of Women's Autonomy, Household Decision-Making, Structural Barriers, and Health System Responsiveness in Afghanistan, Nigeria, Pakistan, and Sudan.

Background: Missed and zero-dose children remain major barriers to polio eradication in settings affected by insecurity, poverty, weak health systems, and social exclusion. This narrative review synthesized evidence on how gender norms and related social determinants influence childhood polio vaccination in Afghanistan, Nigeria, Pakistan, and Sudan. Afghanistan and Pakistan remain the only countries with endemic wild poliovirus transmission, while northern Nigeria, especially areas affected by insurgency, and war-affected Sudan continue to report substantial numbers of polio zero-dose and under-immunized children, together with occasional reports of circulating vaccine-derived poliovirus. Methods: A comprehensive search of peer-reviewed and institutional literature was conducted in major databases and relevant grey literature sources. Eligible studies examined childhood immunization or polio vaccination among children under five and reported gender-related determinants of vaccination uptake. Findings were synthesized thematically. Results: Forty-one studies were included. Five interconnected domains emerged: women's empowerment, autonomy, and household decision-making; male involvement, household gender norms, and family power relations; socioeconomic and structural gender-related barriers; education, information access, community perceptions, and health system responsiveness; and war, insurgency and their gendered impact on childhood polio immunization. Across countries, limited maternal autonomy, restricted mobility, dependence on male decision-makers, poverty, conflict, displacement, misinformation, and weak health services reduced access to vaccination. Supportive male engagement, female health workers, trusted community leadership, and culturally responsive outreach facilitated vaccine acceptance. Conclusions: Gender influences childhood polio vaccination through intersecting household, community, structural, and health-system pathways. Family power extends beyond male decision-making, with women's education and influence within households shaping vaccination decisions. Strengthening women's agency, constructively engaging men (e.g., through husband schools), and delivering culturally responsive services are essential for reaching missed and zero-dose children and accelerating polio eradication.