Inclusion Criteria

Inclusion criteria:

- Male vaccinated with at least one dose of GARDASIL™ after the October 2009 FDA date
of first licensure of GARDASIL™ for males

Exclusion criteria all cohorts:

- Female

- Male vaccinated prior to the October 2009 FDA date of first licensure of GARDASIL™
for males

- Male who received all doses of GARDASIL™ outside of the health plan

Exclusion criteria, Regimen Completers cohort:

- Male < 9 and > 26 years of age at first dose

- Male not part of health plan at each dose

- 3-dose vaccination regimen given over a period > 12 months

- Less than 28-day interval between first and second dose

- Less than 12 weeks between the second and third dose

- Less than 24 weeks between first and third dose

Exclusion criteria, Autoimmune cohort:

- Male with less than 12 months of health plan membership prior to first dose of GARDASIL™