Alternative dosage schedules with HPV virus-like particle vaccines.

HPV vaccines can prevent multiple cancers in women and men. Difficulties in the cost and completion of the three-dose vaccine series have led to considerations of alternative dose schedules. In clinical trials, three doses given within a 12-month period versus the standard 6-month period yielded comparable results, and immunogenicity appears comparable with two doses in adolescent females compared to the three-dose series in adult females. While the data are generally supportive of moving to a two-dose vaccine schedule among young female adolescents, the adoption of a two-dose vaccine schedule still poses a potential risk to the strength and longevity of the immune response. Public health authorities implementing a two-dose vaccine schedule should devise risk management strategies to minimize the potential impact on cancer prevention.