The HPV vaccine is highly effective in preventing infections with high-risk HPV types that cause cervical and other cancers. Different types of HPV vaccines (bivalent, quadrivalent, and nonavalent) show vaccine efficacy ranging from about 80% to nearly 100% against HPV types 16/18 and other cancer-causing types. A single dose of HPV vaccine has shown about 97.5% efficacy in preventing cancer-causing HPV strains for young girls, with protection lasting many years. The vaccine also significantly reduces the incidence of cervical cancer and precancerous lesions by about 86-90% when given before exposure to the virus.
Effectiveness by Vaccine Type
- Bivalent vaccine efficacy against HPV 16/18 infection in naive women: 91–100%
- Quadrivalent vaccine efficacy against HPV types 6/11/16/18: close to 100% against persistent infection and high-grade cervical lesions
- Nonavalent vaccine efficacy against multiple high-risk HPV types: about 95-98% for persistent infections
- Single-dose vaccine efficacy in trials: around 97.5%, lasting up to 11 years or more
Impact on Cervical Cancer and Lesions
- HPV vaccination reduces cervical cancer rates by almost 90% in women vaccinated as preteens
- Reduces incidence of cervical intraepithelial neoplasia grade 2+ (CIN2+) by over 90% in vaccinated naive populations
- Decreases genital warts incidence significantly with quadrivalent vaccine
Longevity and Protection
- Protection from a single vaccine dose comparable to multiple doses, durable up to 10-11 years in studies
- Provides both direct and cross-protection against multiple HPV types
In summary, the HPV vaccine is extremely effective in preventing infections with high-risk HPV types, precancerous cervical lesions, and cervical cancer, especially when administered before HPV exposure. Single-dose schedules are also showing promising efficacy, improving vaccine accessibility while maintaining protection.
