Key takeaways:
- HPV vaccination was associated with a markedly lower risk of high-grade vulvar and vaginal precancerous lesions compared with no vaccination.
- The greatest protective benefit was observed in women vaccinated before age 17, reinforcing the importance of early immunization.
- Vaccinated women had significantly lower incidence rates of high-grade vulvovaginal lesions than unvaccinated women across all age groups.
- Population-level reductions in lesion risk were most evident in younger birth cohorts covered by subsidized or catch-up vaccination programs.
- Findings support expanding early and widespread HPV vaccination to reduce the burden of vulvovaginal precancers and cancers.
Alongside protecting against cervical cancer, human papillomavirus (HPV) vaccination has been linked to reduced odds of developing severe precancerous vulva and vaginal lesions, according to a recent study published in JAMA Oncology.1
The data highlighted a 37-fold reduction in severe lesion risk among vaccinated vs unvaccinated women. Additionally, the most significant benefits were reported in women vaccinated while aged under 17 years, with a risk reduction of 55%.
“Our study is the largest of its kind to investigate the link between HPV vaccination and serious diseases of the vulva and vagina,” said Yunyang Deng, postdoctoral researcher at Karolinska Institutet. “The results highlight the importance of offering the HPV vaccine to girls at an early stage in life, before they become sexually active.”
Assessing lesion risk
The population-based cohort study was conducted to determine the link between HPV vaccination and high-grade vulvovaginal lesions.2 Data was obtained from Swedish population and health care registers and included vaccination data, precancers and cancers, immigration, emigration, birth year and country, residence country, and death.
Women born between 1985 and 1998 who were Swedish residents from 2006 through 2022 were included in the analysis. Follow-up began January 1, 2006, or when a patient reached 10 years of age. Exclusion criteria included death, emigration, any HPV vaccination, loss to follow-up, or high-grade vulvovaginal lesions before the entry date.
Being vaccinated was determined by having received a least 1 dose of the quadrivalent HPV vaccine. An initial diagnosis of high-grade vulvovaginal lesions during follow-up was reported as the primary outcome of the analysis.
These included high-grade vulvar lesions and invasive vulvar cancer, alongside high-grade vaginal lesions and invasive vaginal cancer. Age, calendar year, mother’s birth country, country of residence, annual household income, highest parental education level, and parental history of HPV-related precancers and cancers were reported as covariates.
Incidence of high-grade vulvovaginal lesions
There were 778,943 women included in the analysis, 32.9% of whom received at least 1 quadrivalent HPV vaccine dose. Incident high-grade vulvovaginal lesions were reported in 98 vaccinated patients during follow-up vs 547 unvaccinated patients.
Patients vaccinated at ages 10 to 16 years received their incident dose at a median age of 15 years vs a median age of 18 years for those vaccinated when aged 17 years or older. All groups reported a significant increase in the cumulative incidence of high-grade lesions beginning at the age of 23 years.
The least significant incidence was reported in patients aged 10 to 16 years. Additionally, a crude incidence rate of 3.28 per 100,000 person-years was reported in vaccinated patients, vs 5.72 among unvaccinated patients. This indicated a fully adjusted incidence rate ratio (IRR) of 0.63.
Birth cohort trends and population-level impact
Among patients aged 10 to 16 years at vaccination, the crude incidence rate was 1.98 per 100,000 person-years, vs 5.79 per 100,000 person-years among those aged at least 17 years at vaccination. Fully adjusted IRRs of 0.45 and 0.80, respectively, were reported.
Variations were also reported based on birth cohort. This included a crude incidence rate of 8.90 per 100,000 person-years among women born between 1985 and 1988, vs 5.01 for those born between 1989 and 1992. Finally, the rate was 2.53 for those born between 1993 and 1998. Overall, the data highlighted efficacy from the HPV vaccine toward reducing the risk of vulvovaginal lesions.
“A population-level reduction in high-grade vulvovaginal lesions was observed among birth cohorts vaccinated through subsidized or catch-up programs, highlighting the significance of early and widespread vaccination in lowering the burden of these lesions,” wrote investigators.
References
- HPV vaccine can protect against severe lesions of the vulva and vagina. Karolinska Institutet. December 18, 2025. Accessed January 2, 2025. https://www.eurekalert.org/news-releases/1110187
- Deng Y, Wu S, Ask LS, et al. Quadrivalent human papillomavirus vaccine and high-grade vulvovaginal lesions. JAMA Oncol. 2025. doi:10.1001/jamaoncol.2025.5511
