HPV vaccines.

The ability to generate human papillomavirus virus (HPV)-like particles by the synthesis and self-assembly in vitro of the major virus capsid protein L1 has transformed our prospects for preventing cervical carcinoma in women. These particles provide vaccines that are immunogenic and safe, and data from proof-of-principle efficacy trials strongly suggest that they will protect against persistent HPV infection and cervical intraepithelial neoplasia. However, the duration of protection provided by these vaccines is not known, the antibody responses induced are HPV-type-specific and immunisation must occur pre-exposure to the virus. Second-generation vaccines could include an early antigen for protection post exposure and alternative delivery systems might be needed for the developing world. Therapeutic vaccines for low-grade intraepithelial disease are realistic but high-grade disease presents major hurdles for immunotherapies.