The FDA has approved a new indication for prevention of anal cancer and anal intraepithelial neoplasia in both sexes for the human papillomavirus (HPV) vaccine Gardasil (Merck). This vaccine is already FDA-approved for prevention of cervical cancer and genital warts in females 9-26 years old and for prevention of genital warts in males 9-26 years old. HPV types 6 and 11 cause about 90% of genital warts. Types 16 and 18 cause more than 70% of cervical cancer and about 80% of anal cancer.1 Gardasil is highly effective in preventing infection with HPV types 6, 11, 16 and 18 in both males and females.2,3 (A second HPV vaccine, Cervarix, is also effective in preventing infection with types 16 and 18, but has no activity against types 6 and 11; it has not been approved for any indication in males.4)
Since 40% of women become infected with HPV within 16 months after initiation of sexual activity and neither vaccine prevents cancer if it is given after infection, vaccination against HPV is now recommended routinely for girls 11-12 years old. Routine vaccination of boys with Gardasil would benefit unvaccinated girls as well as the boys themselves.