What Really Pushed HPV Vaccines Into More Countries

Since 2006, safe and effective HPV vaccines have existed. But many low- and middle-income countries took years to start using them. Why the delay? A new study looked at the main policy factors that influenced when countries introduced the HPV vaccine between 2006 and 2025.

The researchers used two methods. First, they applied a generalized linear model (GLM) to test how specific policy events affected vaccine adoption. Second, they ran a changepoint analysis to spot sudden shifts in the rate of country introductions over time.

One finding stood out. The World Health Organization's 2022 recommendation for a single-dose HPV vaccine schedule had the strongest link to more countries starting the program. Around the same time, Gavi, the Vaccine Alliance, expanded its funding support for HPV vaccines from 2017 to 2025. This funding boost also played a role in several models.

When the team compared model projections with and without the one-dose schedule, they estimated that 22.46 additional countries in low- and middle-income regions introduced the HPV vaccine because of this change. The changepoint analysis confirmed a clear jump in introductions starting in 2022.

Overall, the study puts numbers to the biggest global forces behind HPV vaccine uptake. These insights could help guide efforts to make the vaccine more widely available and fairer across countries.