Updated

Federal health advisers say Merck's vaccine Gardasil, which already is used to prevent cervical cancer in women, should also be approved to stop genital warts in men.

A Food and Drug Administration panel voted unanimously with one abstention that the vaccine is effective for blocking the human papilloma virus, or HPV, in males ages 9 to 26. The panel voted 7-1 that the vaccine is safe for those patients.

The FDA is not required to follow the group's guidance, though it usually does.

HPV causes warts and certain rare cancers of the genitals in both men and women.

While an approval decision could theoretically double the market for Gardasil, analysts don't expect much use in males because genital warts usually clear up by themselves.