The vaccine, called Gardasil, protects women against two strains of the human papillomavirus that cause 70% of cervical cancers. At $360 for a series of three shots, it is the most expensive vaccine yet. Medicaid and the federal Vaccines for Children Program will help cover costs. Large private insurers are also expected to pay for the vaccine.

Merck & Co., the maker of Gardasil, this week suspended its lobbying campaign aimed at getting states to require the vaccine for middle-school-aged girls. "It distracted from the real issue, the importance of the vaccine and the ability to save lives," spokesman Chris Loder said.

Critics have questioned [Rick Perry]'s ties to Merck. His former chief of staff is now a lobbyist for the drug maker. And his current chief of staff and other aides reportedly met to discuss the state's immunization program, including the HPV vaccine order, on the same day in 2006 that Merck donated $5,000 to the governor's reelection campaign.