Peer-reviewed article
Transient recovery and renewed decline in HPV vaccination coverage in Cameroon after single-dose and gender-neutral vaccination: a secondary analysis of national immunisation coverage estimates, 2020–2025
Tambe Elvis Akem, Nnam Immaculate Muhzong ·
Summary
Written by AI, not yet AICS's view · claude-sonnet-5-5This study looks at why HPV vaccination coverage among girls in Cameroon rose sharply after a single-dose, gender-neutral schedule began in 2023, then fell in 2024 and 2025. It uses national WHO and UNICEF coverage estimates for 2020 to 2025 and a health policy framework to suggest which operational, policy and system factors may explain the trend. Other childhood vaccines improved in 2025 while HPV coverage stayed much lower, which points to a problem specific to HPV and adolescent delivery rather than a general weakness in the immunisation system. The authors propose a recovery framework that prioritises girls for a limited time.
Key points
- Girls' first-dose HPV coverage rose to 68% in 2023, then fell to 36% in 2024 and 30% in 2025, a net decline of 38 percentage points from the 2023 peak.
- Under the former two-dose schedule, estimated dropout between doses was 76% in 2021 and 70% in 2022.
- In 2023, HPV coverage nearly tripled despite a four-month national and subnational stockout of the first and third doses of diphtheria-tetanus-pertussis-containing vaccine.
- By 2025 all 11 comparator antigens had improved from 2024 but remained well above HPV coverage, and the gap widened for every comparator.
- Suggested recovery measures include reliable supply, protected school-based delivery, strategic communication, outreach for underserved girls, multi-year faith-sector engagement and time-limited girls-first prioritisation.
Limitations
The study is a secondary analysis of national estimates, so it can only suggest plausible explanations for the trend and cannot show what caused the rise and fall. The abstract does not describe any tested intervention or any local data on delivery or demand.
Abstract
Abstract Background Cameroon adopted a single-dose gender-neutral human papillomavirus (HPV) vaccination schedule in January 2023. Girls’ first-dose coverage rose sharply to 68% in 2023 before declining to 36% in 2024 and further to 30% in 2025, representing a net two-year decline of 38 percentage points from the 2023 peak. The central analytical question was what operational, policy, and system factors plausibly account for this trajectory. Methods We conducted a health policy analysis informed by Walt and Gilson’s health policy triangle and a root-cause-to-intervention logic model to address this question and propose an evidence-informed girls-first recovery framework. Primary data were WHO and UNICEF Estimates of National Immunization Coverage (WUENIC) 2025 revision estimates for Cameroon, including HPV first dose and completed series among girls from 2020 to 2025, and coverage for 11 comparator antigens with stable indicator definitions across the 2024 and 2025 revisions. WUENIC Estimate Descriptions and WHO/UNICEF 2025 revision notes were reviewed for documented stockout events and reporting-method context. Results Under the former two-dose schedule, dose-completion attrition was marked: estimated dropout was 76% in 2021 and 70% in 2022. An apparent 2023 supply paradox suggests a plausible role for policy, delivery, and demand-side factors: despite a four-month national and subnational stockout affecting the first and third doses of diphtheria-tetanus-pertussis-containing vaccine, HPV coverage nearly tripled that year. By 2025, all 11 comparator antigens had improved from 2024 while remaining substantially higher than HPV coverage; the HPV-specific coverage gap widened for every comparator antigen assessed. This pattern is consistent with an HPV/adolescent-specific delivery and sustainability barrier rather than general immunisation-system weakness. Conclusions The analysis suggests that renewed recovery may depend on reliable supply, protected school-based delivery, strategic communication, outreach for underserved girls, multi-year faith-sector engagement, and time-limited girls-first prioritisation until enabling conditions for gender-neutral vaccination are restored.