Vaccines work, but we need more information before widespread immunisation

At the beginning of October one of the trials of vaccines against human papillomavirus (HPV) infection, the primary risk factor for cervical cancer, announced an encouraging result.1 Large scale, multi-country, multi-site trials of several HPV vaccines are currently under way. The end points comprise incident and persistent HPV infection (during 2-3 years' follow-up) and associated precancerous cytological and histological lesions (cervical intraepithelial (CIN) neoplasia during 2-3 and 4-5 years'follow-up). The World Health Organization is expecting at least one of these vaccines to be licensed for use in 2006.2 How promising are the available trial results? What other questions need answering? And is it time to accelerate preparations for programmes to provide HPV vaccination?

The latest data release concerns a trial of a quadrivalent recombinant vaccine that included HPV types 6, 11, 16, and 18.1 In all, 12 167 women at 90 centres in 13 countries participated in the trial, the FUTURE II study. In this prospective double blind study, women aged 16 to 26 were randomised to receive three doses of either vaccine or placebo over six months.

In a restricted “according to protocol” analysis that included only women who had no protocol violations and who received a full course of vaccine and were free of infection with HPV types 16 and 18 at month 7, the reported efficacy of the vaccine after an average follow-up of 17 months …