Texas lawmakers are fighting to block the governor‘s order requiring that sixth-grade girls be vaccinated against the virus that causes cervical cancer, with the House giving key approval to a bill to make the shots strictly voluntary. The House voted 119-21 on Tuesday to approve a bill that would keep the vaccine off the list of required shots for school attendance. The measure was likely to get a final House vote Wednesday to send it on to the state Senate.

The vaccine protects girls against some strains of human papillomavirus, or HPV, a sexually transmitted virus that causes most cases of cervical cancer. A February report by the federal Centers for Disease Control and Prevention estimated that one in four U.S. women ages 14 to 59 is infected with the virus.

Lawmakers said the governor circumvented the legislative process.

The governor‘s office has estimated that only 25 percent of young women in Texas would get the vaccine if it is not mandatory.

Critics also have argued that the vaccine, called Gardasil, was too new and its effects needed to be further studied before mandating it for Texas schoolgirls. The Food and Drug Administration approved Gardasil last year.

Although the Wyoming Legislature recently rejected a request for $4 million specifically to fund HPV vaccination, the state‘s Department of Health intends to continue offering the vaccine to eligible girls with existing funding until the money run out.