Austin, Texas ? Bypassing the Legislature altogether, Republican Gov. Rick Perry issued an order Friday making Texas the first state to require that schoolgirls get vaccinated against the sexually transmitted virus that causes cervical cancer.

By employing an executive order, Perry sidestepped opposition in the Legislature from conservatives and parents’ rights groups who fear such a requirement would condone premarital sex and interfere with the way Texans raise their children.

Beginning in September 2008, girls entering the sixth grade will have to receive Gardasil, Merck & Co.’s new vaccine against strains of the human papillomavirus, or HPV.

Perry also directed state health authorities to make the vaccine available free to girls 9 to 18 who are uninsured or whose insurance does not cover vaccines. In addition, he ordered that Medicaid offer Gardasil to women ages 19 to 21.

Perry, a conservative Christian who opposes abortion and stem cell research using embryonic cells, counts on the religious right for his political base. But he has said the cervical cancer vaccine is no different from the one that protects children against polio.

“The HPV vaccine provides us with an incredible opportunity to effectively target and prevent cervical cancer,” Perry said.

Merck is bankrolling efforts to pass state laws across the country mandating Gardasil for girls as young as 11 or 12. It doubled its lobbying budget in Texas and has funneled money through Women in Government, an advocacy group made up of female state legislators.

The order is effective until Perry or a successor changes it, and the Legislature has no authority to repeal it, said Perry spokeswoman Krista Moody. Moody said the Texas Constitution permits the governor, as head of the executive branch, to order other members of the executive branch to adopt rules like this one.