The Future II Study Group.Effect of prophylactic human papillomavirus L1 virus-like vaccine on risk of
cervical intraepithelial
neoplasia grade 2 and grade 3, and adenocarcinoma in situ:a
combined analysis of four randomised clinical trials.Lancet 2007; 369:1861-1868;Markman M.Human papillomavirus vaccine to prevent
cervical cancer.Ibid:1837-1839(comment)
A prearranged combined analysis of four trials has confirmed the potential benefit of human papillovirus vaccine to young women.
A total of 20,583 women , 16 to 25 years old were included in the study. They were randomized to receive quadrivalent HPV 6/11/16/18 vaccine(9,087 women), the HPV 16 vaccine only(1,204) and the placebo(10,292).They were all followed up for three years.Among women previously uninfected with HPV 16 or HPV 18, vaccine efficacy against HPV 16/18 -related cervical intraepithelial neoplasia (CIN) grades 2 and 3, adenocarcinoma in situ (AIS)or cervical cancer was 99 per cent.Among all women, the efficacy was 44 %.Only one case occurred among vaccinated HPV-uninfected women.In an intention-to-treat analysis, there was 18 per cent reduction in the rate of CIN 2/3 or AIS due to HPV type.
Therefore, HPV vaccination can substantially reduce incidence of precancers and cancers