The human papillomavirus (HPV) vaccines save lives by preventing lethal cervical and anogenital cancers. If Henrietta Lacks had received an HPV vaccine, she would not have succumbed to cervical cancer. Yet not enough young men and women receive the vaccine. An obstacle to more widespread adoption of the HPV vaccine is that some parents and clinicians feel that it encourages risky sexual behavior. The results of a recent study indicate that such fears are unfounded.