Which of the following statements regarding the currently licensed human papillomavirus (HPV) vaccine (Gardasil) is true?
ExplanationGenital human papilloma virus is thought to be the most common sexually transmitted infection in the United States. A recent study of initially seronegative college-aged women found 60% became infected within 5 years. This underscores the importance of the recent development of effective vaccines and continued cervical cancer screening strategies. Approximately 20–25% of the U.S. population past 11–12 years old is seropositive for HSV-2. The high prevalence of this infection in the general population is due to several factors including lifelong infection, ongoing transmission during latent infection due to asymptomatic shedding of HSV-2 in the genital mucosa, and high rates of transmission within monogamous partnerships.These features are markedly different than those associated with bacterial STIs such as gonorrhea and syphilis, which require high rates of partner change to persist in subpopulations. HIV-1 infections are still concentrated within high-risk populations (men who sleep with men, injection drug users, high-risk heterosexuals, and immigrants from high prevalence regions). There are two available HPV vaccines. Gardasil (Merck) is currently licensed and contains HPV types 6, 11, 16, and 18; Cervarix (Glaxo-SmithKline) is pending final regulatory approval and contains HPV types 16 and 18. HPV types 6 and 11 cause 90% of anogenital warts. HPV 16 and 18 cause 70% of cervical cancers. Both vaccines consist of virus-like particles without any viral nucleic acid, therefore are not active. Both provide nearly 100% protection against two common oncogenic strains of HPV (16 and 18) but neglect to cover the other strains that cause up to 30% of cervical cancer. Because the vaccines do not protect against all oncogenic HPV serotypes, it is recommended that Pap screening of women for cervical cancer continue according to prior schedules. The vaccine should be given to girls and young women between the ages of 9 and 26 provided that they do not have evidence of infection with both HPV 16 and 18 already
