Scaling Adolescent Immunity: Multi-Age Cohort Human Papillomavirus (HPV) Vaccination Campaigns in West Africa—Evidence from Côte d’Ivoire, Ghana, Liberia, and Sierra Leone

Abstract

Background: Cervical cancer remains a major public health problem, causing approximately 660,000 new cases and 348,000 deaths annually, with more than 90% occurring in low- and middle-income countries. The WHO African Region accounts for approximately 20% of global cases and 30% of deaths. In November 2020, the World Health Assembly adopted the Global Strategy for Cervical Cancer Elimination with 90–70–90 targets for 2030. Multi-age cohort (MAC) campaigns have emerged as a high-impact strategy for achieving population-level HPV vaccination coverage. This study documents the implementation and outcomes of HPV MAC campaigns across Côte d’Ivoire, Ghana, Liberia, and Sierra Leone in 2025. Methods: This multi-country mixed-methods analysis integrated quantitative administrative campaign data with qualitative programmatic assessments across eight operational readiness domains from the WHO Immunization Readiness Assessment Tool. Data were collected between January and December 2025 from national reports, WHO supervision missions, and partner reports. Coverage analysis used administrative data triangulated with independent monitoring. Equity analysis used school enrolment data and geographic accessibility indices. Results: The campaigns targeted 7,376,096 girls aged 9–18 years and reached approximately 6,306,294, achieving 85.5% overall coverage. Côte d’Ivoire, Ghana, Liberia and Sierra Leone reported administrative coverage of 88.0%, 84.5%, 60.0% and 100%, respectively. All four countries achieved the minimum operational readiness threshold of 80% across all assessed domains. A total of 35,860 health workers were trained, with post-training competency scores increasing from 58.8% to 89.5%. Cold chain functionality exceeded 98% across all campaigns. A total of 314 cases of Adverse Events Following Immunization (AEFIs) were reported, all classified as mild, giving an approximate rate of 5.0 per 100,000 doses. Coverage gaps between in-school and out-of-school girls ranged from 18 to 35 percentage points. Conclusions: The findings suggest that large-scale adolescent HPV immunization can be successfully implemented in resource-limited settings when supported by political commitment, multisectoral coordination and adequate operational resources. The single-dose schedule transition under Gavi 6.0 offers opportunities to simplify delivery. Priority actions include integrating HPV into routine immunization, scaling equity strategies for out-of-school girls and ensuring sustainable financing.