HPV Vaccination Reduces Risk of Vulvar and Vaginal Precancerous Lesions: JAMA
A population-based study from Sweden’s Karolinska Institute found that women and girls who received at least one dose of the HPV vaccine had a 37% lower risk of developing precancerous lesions of the vulva and vagina compared with unvaccinated individuals. Published in JAMA Oncology, the findings emphasize on broader protective benefits of HPV vaccination beyond cervical cancer prevention. The study was conducted by Yunyang D. and colleagues.
The main aim was to assess the relationship between quadrivalent HPV immunization and the rate of vulvovaginal high-grade lesions, vulvar, and vaginal cancers. The secondary objective was to determine if the rate of reductions in populations exposed to different strategies concerning HPV immunizations differed by birth year.
This nationwide population-based cohort analysis was performed in Sweden on women born between 1985 and 1998 who lived in the country between 2006 and 2022. A woman was eligible for the analysis if she had no prior HPV vaccination and no previous high-grade vulvovaginal lesions. Data analysis was done from February to October 2025. Vaccine exposure was considered a time-varying variable to calculate the risk of the outcome over a follow-up period.
The participants were grouped according to receipt of at least one dose of quadrivalent HPV vaccine. The birth cohorts were categorized according to the overall national immunization plans, with women born in 1985 and 1988 eligible only for opportunity-driven immunizations, women born in 1989 and 1992 eligible for subsidized immunizations, and women born in 1993 and 1998 eligible for organized catch-up immunization campaigns. The age at immunization was additionally checked, with main comparisons of immunization performed at ages 10-16 years compared with immunization at age 17 years or later.
Key findings
A total of 778 943 women were studied, and 256 353 women (32.9%) were administered at least one dose of the quadrivalent HPV vaccine.
A total of 98 high-grade vulvovaginal lesions were seen among women receiving the vaccine and 547 high-grade vulvovaginal lesions were seen among unvaccinated women.
There was significantly lower incidence of high-grade vulvovaginal lesions among women receiving the HPV vaccine with an incidence rate ratio 0.63 (95% CI, 0.50–0.81) than that seen among unvaccinated women.
The protective association was strongest in women who were HPV vaccine recipients at young ages.
Women HPV vaccine recipients between 10-16 years had the incidence rate ratio of 0.45 (95% CI, 0.32-0.65) compared to those HPV vaccine recipients at 17 years or older with an incidence rate ratio of 0.80 (95% CI, 0.61-1.06).
HPV vaccination was significantly associated with a lower incidence of high-grade vulvovaginal lesions, with the strongest associations being seen in those vaccinated at age < 17 years. Also notable in support of HPV vaccination is the evidence for population-level reductions in HPV-related outcomes across successive birth cohorts. These observations support the importance of increased vaccination coverage in younger age groups in efforts to reduce vulvovaginal lesions and cancer.
Reference:
Deng Y, Wu S, Ask LS, et al. Quadrivalent Human Papillomavirus Vaccine and High-Grade Vulvovaginal Lesions. JAMA Oncol. Published online December 18, 2025. doi:10.1001/jamaoncol.2025.5511
