By now, you're probably aware of the hype over a vaccine associated with these three letters: HPV. Designed to prevent people from acquiring human papillomavirus, some strains of which can lead to cervical, vulval, anal and vaginal cancer in women not to mention cancers of the anus and penis in men, the HPV vaccine has been thrust into the spotlight again during the recent debates among the GOP presidential candidates.

The controversy centers on Texas Gov. Rick Perry, who issued an executive order in 2007 that required all sixth-grade girls in his state to undergo HPV vaccination. That order has become a target for some of Perry's opponents, who claim that the governor overstepped his boundaries by mandating the vaccine and put patients at risk of dangerous side effects. Michele Bachmann told a tale of a tearful mother who claimed her 12-year-old daughter was now mentally disabled because of the vaccine.

To date there is no research that supports a link between the HPV vaccine—or any other vaccine for that matter—and mental retardation. In the past few days, news outlets across the country have seized on the issue, debunking Bachmann's story (from which she has subsequently backpedaled). For example, this round-up of the relevant research on vaccines and their side effects cites an August report from the Institute of Medicine that found no link between any vaccine and mental disability. Similarly, a story in the New York Times points out that the HPV vaccine has nothing to do with mental disability, saying flat-out that "there is no evidence linking it to mental retardation." A story in the Los Angeles Times also debunked Bachmann's claim and cited the American Academy of Pediatrics, which stated that Bachmann's claim had "absolutely no scientific validity." And four experts asked by to weigh in on the pros and cons of mandatory vaccination don't all agree that it should be required, but do agree that the vaccine is safe and effective.

Scientific American also has recently covered the lack of scientific evidence linking vaccines to autism as well as the dangerous public health consequences that can follow when parents refuse to vaccinate their children.