ATLANTA — 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.