The Food and Drug Administration (FDA) has approved a new indication for the vaccine Gardasil-the prevention of genital warts caused by human papillomavirus (HPV) types 6 and 11 in boys and men ages nine to 26. HPV is the most common sexually transmitted disease in the United States, and the warts it causes can be treated with topical medication or cryotherapy, or surgically removed. (HPV is also associated with cancer of the cervix, vagina, vulva, anus, and penis, as well as of the tongue, tonsils, and throat.)

Gardasil, which is nearly 90% effective in preventing genital warts, is already indicated for use in girls and women ages nine through 26 for the prevention of cervical, vulvar, and vaginal cancer caused by HPV types 16 and 18, for the prevention of precancerous or dysplastic lesions caused by HPV types 6, 11, 16, and 18, and for the prevention of genital warts caused by HPV types 6 and 11. In patients of either sex, Gardasil is administered in three injections over a six-month period. The most common adverse effects associated with the vaccine are headache, fever, and pain, swelling, and redness at the injection site.

Cervarix, a new vaccine for the prevention of cervical cancer, has been approved for use in girls and women ages 10 to 25. Cervarix is about 93% effective in preventing precancerous cervical lesions caused by HPV types 16 and 18 in patients not already infected with either virus, and it is the first vaccine licensed by the FDA to include monophosphoryl lipid A (MPL) as an adjuvant; MPL in combination with aluminum hydroxide is the adjuvant ASO4. The most common adverse effects of the new vaccine are pain, redness, and swelling at the injection site, fatigue, headache, muscle and joint aches, and gastrointestinal distress. As with Gardasil, three doses of Cervarix are administered over a period of six months. The vaccine is not approved for use in pregnant women, and postmarketing studies will assess its safety in that population when administered prior to awareness of pregnancy.