Meta-analysis: Three doses of the bivalent (Cervarix) and quadri-valent (Gardasil) vaccines offered significant protection against cervical adenocarcinoma in situ associated with HPV16 and HPV18 among young women (aged 15–26 years): 88% (95%CI 30–98%). Trials among vaccine recipients not already infected with HPV showed high efficacy against high-grade cervical, vulvar and vaginal lesions: 98% (95%CI 93–100) for CIN2+ and 100% (95%CI 83–100) for vulvar and vaginal intraepithelial neoplasia grade 2+ caused by the HPV types in the quadrivalent vaccine. Approval of the 2-dose schedule was based on demonstration of non-inferiority of the immune response when compared with young adult women (16-26 years of age) in whom 3-dose efficacy has been proven (immunobridging). A one-dose schedule is supported by WHO given that post-hoc analyses of efficacy trials, and post-licensure observational studies among African females (15-20 years of age) have demonstrated that a single dose of HPV vaccine is sufficient to elicit an immune response that provides similar protection as a multidose regimen against initial and persistent HPV infection.
Efficacy and effectiveness estimates (e.g. against infection, disease, hospitalization, death), including in different populations
