Released amid a flurry of controversy in 2006, Gardasil, the first vaccine against human papillomavirus, or genital warts, was hailed by some as a chance to drastically reduce rates of cervical cancer, which affects women infected with HPV. Anxious parents saw schools’ recommendations that pre-teens get the vaccine as a tacit approval of premarital sexual activity. Either way, it stands as one of the most important vaccines developed in the last decade—cervical cancer kills almost 4,000 American women annually.