Single-Dose HPV Vaccination

Of the 152 countries that have introduced HPV vaccines into their national immunization programs or have introduced subnationally, 76 countries (50%) use a single-dose schedule as of July 2025. Eleven of these countries introduced the HPV vaccine into their national immunization programs using a single-dose schedule, while the majority (65, or 86%) initially introduced HPV vaccines with a two- or three-dose schedule but switched to a single-dose schedule after the updated WHO recommendation. 

Most countries using a single-dose schedule are middle-income countries (32% lower-middle-income and 40% upper-middle income), though low-income and high-income countries are also represented (14% each). Most Gavi-eligible countries have adopted a single-dose schedule (25 of 30, or 83%). Current Gavi funding guidelines allow countries to select either a one- or two-dose schedule, though they encourage the use of a single-dose schedule [10]. Countries using single-dose schedules are also spread geographically, with all WHO regions represented, as seen in the graph below.

Among countries that use a single-dose schedule:

• The quadrivalent HPV vaccine (Gardasil 4) is the most common (used in 54 countries).
• More than two-thirds of countries implement HPV vaccines through school-based delivery, rather than through health facilities.
• Most countries target only girls in their programs, while the rest have gender-neutral programs (targeting both boys and girls).

Although several high-income countries adopted a single-dose schedule following the WHO recommendation—Australia, Canada, Ireland, Spain, and the United Kingdom—the United States and many other high-income countries continue to use a two-dose schedule. 

Benefits of a Single-Dose Schedule

Lasting Protection

The inclusion of a single-dose schedule in WHO’s HPV vaccine recommendations was based on multiple studies finding that one dose of the HPV vaccine can provide comparable efficacy and duration of protection to a two-dose schedule [11]. Researchers have found that one dose of HPV vaccine can provide 92% vaccine efficacy against persistent HPV 16 and 18 infection, a proxy for protection against cervical cancer, with no statistically significant differences in efficacy between 1, 2, or 3 doses [12]. These results are consistent across various trials [13,14].

Studies following women over time found that a single dose of the HPV vaccine continued to provide stable immune response throughout the study period [15], with one study following women for 16 years [16]. Based on this evidence, researchers project that a single dose of the HPV vaccine can prevent HPV infection for at least 20 years (and likely longer) after vaccination, protecting women during the time when they are most at risk [16].

Simplified Implementation

HPV vaccination targets adolescents between 9 and 14 years old, a population that generally has fewer interactions with routine immunization programs, and so these programs are typically more complicated than routine immunization programs for young children. A single-dose schedule would eliminate some of these complexities, such as the burdensome task of tracking and following up with girls who are overdue for their second dose. 

Economic Savings

From a financial perspective, since the high price tags associated with HPV immunization are driven largely by the cost of procuring the vaccine itself [17], this expense would be essentially halved with the implementation of a single-dose schedule. Another significant cost of HPV vaccination programs is service delivery. Unlike most other routine vaccines, HPV vaccines are often administered in community settings, such as schools, to most effectively reach the target population, requiring health workers to travel to vaccination sites. HPV vaccination programs also require health workers to undergo additional training and perform social mobilization activities on top of their normal work duties. Modeling analyses demonstrate that a single-dose schedule can greatly lower the cost of delivering HPV vaccines by decreasing the number of vaccination sessions and thereby reducing per diems and other payments to health workers, vehicle rental and fuel costs, and costs associated with cold chain maintenance and waste management [18]. Analysis of HPV vaccination in four LMICs estimated that switching from a two-dose to a single-dose schedule increases the cost per dose but decreases the cost per fully immunized adolescent by up to 50% [19]. These cost savings would be especially beneficial in non-Gavi-eligible countries as well as those expected to transition out of Gavi support. Alternatively, cost savings could be reinvested to provide catch-up HPV vaccination to older girls, a strategy that would help to accelerate cervical cancer elimination.
 

Key Takeaways

• Compared to a multi-dose schedule, a single dose of HPV vaccine provides comparable efficacy and duration of protection.
• More than 80% of Gavi-eligible countries and half of all countries that have introduced HPV vaccination use a single-dose schedule, illustrating the broad appeal of this approach.
• Countries that have yet to introduce HPV vaccination should consider the use of a single-dose schedule to address existing financial and programmatic barriers to introduction.
• Countries that have already introduced HPV vaccination should consider switching to a single-dose schedule to optimize program implementation and increase coverage, accelerating progress toward cervical cancer elimination goals.
   

Additional Resources

The Power of a Single Dose: Evidence for a Single-Dose HPV Vaccine Schedule [IVAC]

Decision-Making Considerations and Drivers of Country-Level Adoption or Switch to a Single-Dose HPV Vaccination Schedule: A Global Assessment [JSI / HAPPI]

Single-Dose HPV Vaccine Evaluation Consortium [PATH]