Human Papillomavirus Vaccines

Abstract

Human papillomavirus (HPV) infection and HPV-associated anogenital diseases, such as warts, cancers precursors, as well as anogenital invasive cancers, are significant health care problems (Fig. 11.1). Current estimates of the worldwide prevalence of HPV indicate that approximately 10% of women in the general population will harbor cervical HPV infection at a given time (de Sanjose et al., 2007). Furthermore, estimates of human cancer incidence linked to infectious agents suggest that HPV infections in female individuals presently contribute to more than 51% of cancer cases, whereas infection in male individuals accounts for slightly more than 4% of HPV-associated neoplasias (Hausen, 2008). Cervical cancer causes considerable morbidity and mortality in the young female population and con­stitutes a significant economic burden to developing countries. According to 2002 data from the International Agency for Research on Cancer (Parkin et al., 2005), approximately half a million women worldwide develop cervical cancer every year (Fig. 11.1), and over two-thirds of these cases are associated with HPV infection of either oncogenic type 16 (51.0%) or HPV type 18 (16.2%). Consequently, successful strategies that can protect against HPV infection are expected to decrease the rates of HPV-related diseases. Sexual abstinence is the most effective preventive measure against HPV infection and other sexually transmitted diseases (STDs). Although Winer et al. (2006) reported that the regular use of condoms may reduce the risk of genital HPV infection, transmission to the unprotected perigenital skin can still occur.