HPV

By William L. Atkinson, MD, MPH and Andrew T. Kroger, MD, MPH

HPV is the most common sexually transmitted infection in the United States. Currently, more than 20 million men and women in the United States are infected are infected with HPV, and more than 6 million are estimated to become infected. HPV is most common in young men and women in their late teens to early 20s. By age 50, over 80% of sexually active women will have acquired HPV infection.

HPV infection can lead to cervical cancer in women as well as to other cancers that can affect males of females. Cervical cancer is diagnosed in more than 9,700 women each year in the United States and causes 3,700 deaths. Seventy percent of cervical cancers are caused by strains of HPV included in the new HPV vaccine. HPV also causes genital warts in men and women.

Gardasil, manufactured by Merck, is the first vaccine developed to prevent cervical cancer, pre-cancerous genital lesions, and genital warts due to HPV. The vaccine is highly effective against four types of the HPV virus, including two that cause about 70 percent of cervical cancer. HPV-vaccine recipients who have not acquired HPV would get the full benefits of the vaccine. Though women already infected with an HPV vaccine type virus will not benefit from that part of the vaccine, they could still benefit from the other vaccine type virus.

The Advisory Committee on Immunization Practices (ACIP) voted to recommend that it be routinely given to girls ages 11-12 years, though it can be given to girls as young as 9 years. ACIP also voted to recommend that that girls and women ages 13 through 26 years receive the vaccine. Ideally vaccine should be administered before sexual activity, but sexually active females should still be vaccinated.

Gardasil is licensed as a 3-dose series, with dose #2 given 2 months after dose #1, and dose #3 given 4 months after dose #2. The vaccine should be given IM in the deltoid.