Genital human papilloma virus (HPV), the most common sexually transmitted disease in the United States, is associated with cervical cancer in women, and penile cancers in men. The infection is asymptomatic until a malignancy develops. Of the more than 90 subtypes, only a small number are associated with malignancies. Vaccines made with recombinant HPV proteins have been shown effective in preventing infection with the more virulent strains of the virus.