Toward a human papillomavirus vaccine.

Much progress has been made over the past 10 years with regard to development of a vaccine active against HPV. Successful protection has been achieved in animal models using species-specific papillomaviruses; however, HPV diversity may delay the development of successful HPV vaccines, especially those designed as therapeutic vaccines for the treatment of HPV-induced carcinoma and high-grade dysplasia of the cervix. Difficulties arise with regard to assessment of efficacy of potential vaccines. The impetus for long-term studies on vaccine efficacy will initially stem from in vitro evidence of responsiveness to the vaccine. The time when a vaccine will have an impact on the prevalence of high-grade dysplasia and invasive cancer is still some way off.