Lansing, Mich. ? Michigan girls entering the sixth grade next year would have to be vaccinated against cervical cancer under legislation backed Tuesday by a bipartisan group of female lawmakers in Lansing.

The legislation is the first of its kind in the United States, said Republican state Sen. Beverly Hammerstrom, lead sponsor.

The vaccine was approved by the Food and Drug Administration in June for use in girls and women and has been hailed as a breakthrough in cancer prevention. It prevents infections from some strains of the sexually transmitted human papilloma virus, which can cause cervical cancer and genital warts.

A government advisory panel said that ideally, the vaccine should be given before girls become sexually active.

The American Cancer Society estimates that cervical cancer will be diagnosed in 9,700 women nationwide, and that 3,700 will die.