A U.S. government medical panel is recommending that a vaccine to prevent cervical cancer in girls should be given to boys as well to help stop the disease.

The panel is urging the U.S. Centers for Disease Control and Prevention to formally recommend vaccinating 11- and 12 year-old boys against the human papillomavirus, known as HPV.

Along with preventing genital warts and cancers linked to the virus, the panel says the vaccine can also prevent the transmission of HPV to girls during sex. The vaccine has been available to boys for two years.

Doctors say not enough girls are being given the HPV vaccine, partially because of fears and misunderstanding by parents.

Doctors say girls as young as age nine should be given the shot to prevent cervical cancer.

But the vaccine is not without controversy. Republican presidential candidate Michele Bachmann said during a debate that a mother told her the vaccine caused mental retardation in her daughter. Medical experts dispute the mother's claim.