Federal vaccine advisers on Thursday began the delicate task of deciding whether a vaccine against sexually transmitted infections that can result in genital warts and cancers should be used more widely in boys and young men.
Concerns about whether to vaccinate against a sexually transmitted disease are made even more charged because much of the serious disease results from homosexual sex. The advisers must also decide whether vaccinating boys would divert scarce resources from a vaccination campaign for girls that has had poor results.
And some of the advisers debated whether preventing genital warts in men — another benefit of the vaccine, for the human papillomavirus, or HPV — was worth the expense. Dr. Franklyn Judson, a member of the government’s Advisory Committee on Immunization Practices and a professor at the University of Colorado, said that few men cared much about genital warts.
“In fact, 50 percent of patients who end up being diagnosed in an S.T.D. clinic didn’t even notice them or were not overly concerned about them,” Dr. Judson said.
But Dr. James C. Turner, a liaison to the committee from the American College Health Association, said that no man in the room would agree that genital warts were of little concern, “not because of the medical consequences, but because of the social consequences.”
“I would say that the men that I see would rate genital warts on the quality scale just above death,” Dr. Turner said, to laughter.
HPV is known to cause cervical, anal and some head and throat cancers, as well as genital warts. The virus can be passed through intercourse, anal or oral sex, and even kissing.
Of the two HPV vaccines on the market — Gardasil, made by Merck, and Cervarix, made by GlaxoSmithKline — only Merck’s has been approved for use in both sexes.
Dr. Richard M. Haupt, from Merck Research Labs, reviewed study data showing that Merck’s vaccine provided protection against the lesions that can lead to anal cancers. But that vaccine costs about $100 per dose, and three doses must be taken to provide full protection against the four strains of the disease represented in the vaccine.
Whether the cost of vaccinating all boys is worth preventing what the Centers for Disease Control and Prevention has estimated is fewer than 5,000 cases of possibly vaccine-preventable cancers is uncertain. Vaccinating males also helps prevent cervical cancer in their female partners.
A study presented to the government advisory committee suggested that when the vaccination rate in females is low — as it is now — vaccinating males is not as cost-effective as a program that improved immunization rates in females. And when vaccination rates in females are high, vaccinating males is not cost-effective.
Anal-cancer rates have been on the rise in recent years, in part because gay men who are infected with H.I.V. have, as a result of improved treatments, been living long enough to develop such cancers.
Fewer than 1 percent of boys ages 11 to 17 have been immunized against HPV, although Dr. Turner said that on college campuses the share of vaccinated men is closer to 15 percent.