Vaccination to prevent human papillomavirus infections: From promise to practice

points• A large proportion of the disease burden related to infection with human papillomavirus (HPV), the most common sexually transmitted infection, can be prevented through vaccination.• There is inequity in access to HPV vaccines, and populations with the largest burden of HPV-related diseases have the least access to the vaccines.• Affordability and sustainable financing of HPV vaccination are barriers to introduction in low-and middle-income countries because of the relatively high cost of the vaccine and its delivery to a nontraditional target population. Global burden of HPV-related diseasesHuman papillomavirus (HPV) is the most common sexually transmitted infection (STI) and can cause HPV-related cancers, most of which are cervical cancers, and genital warts.Although the majority of HPV infections are asymptomatic with spontaneous resolution, disease may result from persistent infection with high-risk HPV genotypes.While infection with a high-risk oncogenic HPV type is the underlying cause of virtually all cases of cervical cancer, most infections with high-risk HPV types do not lead to cancer.This is because infection persists only in a small percentage of people; only a small proportion of these persistent infections progress to precancer, and, of these, even fewer lead to invasive cancer [1].Two HPV types (16 and 18) cause 70% of cervical cancers and contribute to other, less prevalent, noncervical cancers.HPV infections are responsible for nearly all of the 528,000 estimated cervical cancer cases in women each year, accounting for nearly 266,000 deaths yearly [2].High age-standardised rates of cervical cancer are observed in parts of sub-Saharan Africa, Latin America, and Southeast Asian regions.Low rates are seen in the Eastern Mediterranean region as well as in North America, Western Europe, and Australia [2].HIV-positive women have a 5-fold elevated risk of developing cervical cancer.Two additional HPV types (6 and 11) are responsible for up to 90% of anogenital warts [1].Anogenital warts are a common manifestation of HPV infection among young men and women.The overall reported annual incidence (for males and females combined) of anogenital warts (including new and recurrent) ranges from 160 to 289 per 100,000, with a median of 194.5 per 100,000.The estimated median annual incidence of new anogenital warts is 137 per 100,000 among males and 120.5 per 100,000 among females [3].Rates are higher in HIVinfected populations such as those in sub-Saharan Africa (2.4% to 14%) [4].