Parents and guardians could opt their children out of receiving the shot for religious and other reasons. This executive order by Perry has made national headlines. One reason–Gardasil was only approved by the FDA less than a year ago.

Texas Gov. Rick Perry is so enthusiastic about Gardasil that a week ago, he ordered all girls in the state to be immunized before entering sixth grade, as of September 2008. Prompted in part by a vigorous lobbying campaign by Merck, which stands to earn billions of dollars if the vaccine is required, legislators in 23 other states and the District of Columbia have proposed mandating vaccination against HPV for girls as young as 11.

Gardasil may well be the huge medical breakthrough it appears to be. But a rush to make it mandatory, less than eight months after FDA approval, could have detrimental consequences. Among the reasons to move more deliberately:

•Scientific uncertainty. The history of new drugs and vaccines is that unexpected adverse events might not be detected until after millions of people have used them, and the FDA does a poor job of tracking post-approval effects.

Often times, side effects of medications and vaccines are not shown until they have been taken by millions.

Lawmakers in Texas have filed bills that would override the order.