You know those parents who think that giving HPV shots to young girls encourages them to have (unsafe) sex? Maybe it's not something we can blow off as hysteria.
A study of 339 girls aged 13-21 done at the Cincinnati Children's Hospital (serving low-income populations) showed that while most girls understand the extend of the vaccine's protection, 23.6% of them believed that the HPV vaccine lowered their risk of getting other sexually transmitted diseases (though not necessarily that they are completely protected and will have unsafe sex, as we might claim and get ahead of ourselves). The cure for this is, of course, better education!
The paper and other experts report this as a low percentage, and indeed only ~4% thought they could get away with less safe sex practices after the shots. Still, 23.6% misinformation seems pretty high to me, even if it isn't "widespread." However, what's slightly more interesting are the other social factors examined in the paper. Risks for unsafe sex include belief that one is not at risk, alcohol use (since "good girls" are more concerned with safe sex?), misunderstanding or negative attitude towards healthcare by the mother, and getting information from a teacher rather than other sources.
The paper! or U.S. News Article
Also, did you know? HPV is the most common STI in the U.S., with more than half of adults getting exposed.