Experts Consider One-Dose HPV Vaccination for Preteens

The HPV vaccine has been used for 20 years to prevent infections linked to genital warts and cancers affecting the genital areas, mouth and throat. HPV contributes to nearly 50,000 U.S. cancer diagnoses each year, and the CDC attributes about 90% of cervical and anal cancers to HPV. The vaccine is available from age 9 through the 20s, with routine focus on ages 11 and 12 because protection works best before sexual activity.

The question about reducing the schedule gained momentum after a study in Costa Rica followed more than 20,000 girls for five years. One dose offered about 97% protection against cervical cancer, comparable to two doses. In 2024, those findings and other research led a CDC advisory group to examine a possible change, while the American Academy of Pediatrics has also been weighing whether one dose could work for some children and when vaccination should start.

Evidence is not equally strong across all groups. Research supports one dose for preventing cervical cancer in girls, but there is less information about other HPV-related cancers in girls and about protection for boys. A January federal order to move to one dose was stopped by a federal judge. For now, medical experts continue to recommend two shots. Vaccination rates have stayed around 63% of teenagers receiving both doses, below some other adolescent vaccines, while studies have found lower HPV infections, genital warts and precancerous cervical changes after vaccination.