HPV vaccination demonstrates substantial protective effects against high-grade vulvovaginal lesions, with a 70% reduction in risk among Swedish women followed for up to 17 years. The quadrivalent vaccine showed consistent benefits across 778,943 participants, with strongest protection observed when administered during adolescence before sexual debut. This extends HPV vaccine's proven benefits beyond cervical cancer prevention to include vulvar and vaginal precancerous and cancerous lesions. The finding fills a critical evidence gap, as most HPV research has focused on cervical outcomes despite the virus causing cancers throughout the lower genital tract. The population-level analysis reveals how different vaccination strategies—from opportunistic programs to systematic catch-up campaigns—translate into measurable disease reduction. For women's health, this represents validation of current vaccination policies and supports expanding coverage to maximize protection. The study's strength lies in its national registry design and extended follow-up, though the observational nature means residual confounding remains possible. Given that vulvovaginal cancers have limited treatment options and significant morbidity, prevention through vaccination becomes particularly valuable. This evidence should reinforce clinical recommendations for timely HPV vaccination and may influence screening protocols for vaccinated populations.