1. Specific Aims and Overview: The investigators propose a randomized, open label trial of HPV vaccine among males 18-24 years old, comparing an on-time administration of the third dose with delayed administration of the third dose. All participants would receive the first and second doses according to schedule. They would be randomized to either Dose 3 at 6 months or Dose 3 at 12 months.~Blood would be drawn for titers at twice from all participants: pre-dose 1 and one month post Dose 3.~No cytology studies or DNA studies will be conducted.~1.1 Aims:~Determine if delay in the third dose is immunologically non-inferior to the standard administration schedule (1 month post-dose 3).~Determine the side effect profile of a delayed third dose, in comparison to the standard schedule.~Determine the preference and compliance of the men for the timing of the third dose.~1.2 Hypothesis for non- inferiority:~The GMTs in the test group (T) are non-inferior to the usual timing control group (C):~H0: δ ≤ -δ0 versus H1: δ > -δ0 where δ = log (GMTT )- log (GMTC) and δ0 is the pre-specified non-inferiority margin.
The investigators propose a randomized, open label trial of the immunogenicity of HPV vaccine among males 18-24 years old, comparing an on-time administration of the third dose with delayed administration of the third dose. All participants would receive the first and second doses according to schedule. They would be randomized to either Dose 3 at 6 months or Dose 3 at 12 months.~Hypothesis: The Geometric mean titers in the 12 month test group (T) are non-inferior to the usual timing control group (C):~H0: δ ≤ -δ0 versus H1: δ > -δ0 where δ = log (GMTT )- log (GMTC) and δ0 is the pre-specified non-inferiority margin