Global policy determinants of national human papillomavirus vaccine introductions in 2006-2025

Although safe and effective human papillomavirus (HPV) vaccines have been available since 2006, national introduction in low- and middle-income countries (LMICs) has progressed slowly. HPV vaccine adoption may have been shaped by evolving World Health Organization (WHO) recommendations, funding policies of Gavi, the Vaccine Alliance, and the disruption from the Coronavirus Disease 2019 pandemic. However, their relative contributions have not been quantified.

This study analyzed policy determinants of national HPV vaccine introduction rate in LMICs from 2006 to 2025, using: (i) generalized linear model (GLM) to assess predetermined policy events, and (ii) changepoint analysis to identify shifts in adoption trends.

Across a range of GLMs exploring different events and outcome variables, WHO's one-dose recommendation in 2022 was most strongly associated with an increase in country introductions, with the expansion of Gavi's funding policy for HPV vaccines (2017-2025) also important in some models. Comparing model projections with and without the one-dose schedule yielded an estimated 22.46 additional national HPV vaccine introductions in LMICs. Changepoint analysis identified a significant increase in introductions in 2022.

These results quantify the primary global drivers of HPV vaccine uptake, offering actionable insights for expanding equitable vaccine access.