Gardasil, the vaccine used to immunize girls and young women against the sexually transmitted virus that causes cervical cancer, may now be given to boys and young men to protect them from genital warts, a federal advisory group recommended Wednesday.

But the panel of independent medical experts stopped short of urging its routine use in boys, as it has recommended for girls. And members questioned whether vaccinating boys was a cost-effective way to protect their future sexual partners against cervical and other types of cancer caused by human papillomavirus, or HPV.

Gardasil, made by Merck, works against four strains of the virus  two strains that are responsible for 70 percent of cervical cancers and two strains responsible for about 90 percent of genital warts. But it is expensive, requiring a series of three injections that cost $130 each.

The vaccine was approved last week by the Food and Drug Administration for use in boys and men ages 9 to 26. Wednesday’s action, by the Advisory Committee on Immunization Practices of the Centers for Disease Control and Prevention, is intended to guide national policy on use of the vaccine; its recommendations are typically adopted by professional medical associations and set the standards of practice for physicians.