Potential mechanisms for HPV vaccine-induced long-term protection

Human papillomaviruses (HPVs) are small double-stranded DNA viruses that infect the skin and internal squamous mucosae. These viruses were once considered to be the causal agent only of skin or genital warts—lesions of trivial significance. It turns out, however, that HPVs belong to a large virus family that includes individual types that are major global carcinogens causing an estimated 4–5% of all cancers, mainly, but not exclusively, in the anogenital tract of men and women [1]. Even the “trivial” warts, particularly those occurring on the anogenital skin or in the larynx, result in substantial morbidity and are a major health-economic burden [2]. Vaccination is the most effective means that we have of preventing infectious disease, and during the past decade the development of prophylactic vaccines that target infection with the major pathogenic HPVs gives the possibility of controlling these infections and their disease sequelae.