Texas Gov. Rick Perry (R) signed an executive order mandating that girls entering the sixth grade receive a human papillomavirus vaccine beginning in September 2008. Merck's HPV vaccine Gardasil and GlaxoSmithKline's HPV vaccine Cervarix in clinical trials have been shown to be 100% effective in preventing infection with HPV strains 16 and 18, which together cause about 70% of cervical cancer cases.

Perry said that parents who do not want their daughters to receive an HPV vaccine "for reasons of conscience, including religious beliefs," will be able to opt out of the requirement. Last year, 1,169 new cervical cancer cases were reported and about 400 women in Texas died from the disease.