To the Editor: Mr Gostin made an important point in his Commentary on mandatory HPV vaccination: “Above all, health policy must be driven by science.”1 However, the author's recommendation that “if voluntary vaccination proves unsuccessful, states should seriously consider compulsory vaccination laws without generous exemptions” appears premature. As Gostin noted, clinical trial evidence has not demonstrated that HPV vaccines can actually prevent invasive cervical cancer, let alone cervical cancer deaths.2,3 Because HPV vaccines were specifically developed to protect against cervical cancer, we conclude that in the absence of long-term data, their true benefits remain speculative. The Food and Drug Administration acknowledges that “It is believed that prevention of cervical precancerous lesions is highly likely to result in the prevention of those cancers.”4