The anogenital epithelium of a majority of the sexually active population is likely to experience infection with a number of human papillomavirus types. 

In most, infection will be asymptomatic and resolve, with or without transient seroconversion. In some, infection will progress to low-grade anogenital lesions associated with episomal HPV virions, which may or may not resolve spontaneously. In a very few individuals, higher-grade dysplasia which may process to squamous cell carcinoma, associated with integration of HPV genotype(s) ('high risk' versus 'low risk'), and immunosuppression are clearly two such factors. The limitations of drug and ablative therapies warrant an immunomodulatory approach to control of disease. HPV open to attack by an appropriately vaccine-primed immune response. The biology of HPV provides several distinct avenues of attack, namely prevention of infection, therapy for infection, and therapy for HPV-associated neoplasia, and each demands a different vaccine strategy. Which strategy will prevail at the population level is likely to depend on considerations which are fiscal and cultural as well as scientific.