Comparing Immune Response of 2 vs 3 HPV Doses (27-45 Years Old)

The investigators are studying an alternate dosing regimen of an approved drug (9vHPV vaccine) in the population for which it is approved. The vaccine is approved for individuals ages 9-45 years old and participants in this study will be 27-45 years of age. The purpose of the study is to examine the immune response of 2 doses of 9vHPV vaccine. The current recommendation is to administer the vaccine in 3 doses (administered at 0, 1-2 months and 6 months) to those 15-45 years of age, but only 2 doses (administered at 0 and 6 months) if the vaccine series is initiated before age 15. The investigators will conduct a randomized study to determine if 2 doses of elicit a similar immune response to that of a standard 3 dose series in individuals 27-45 years of age. Participants in the study group will receive 2 doses of at 0 and 6 months. Participants in the control group will receive 3 doses of 9vHPV vaccine at 0, 2 months, and 6 months. All participants (target accrual n=618) will have 5 mLs of blood drawn at 0, 1, 7, and 12 months. Following the 12-month blood draw, participants randomized to 2-doses will be offered the 3rd dose. Potential participants will be recruited through the University of Texas Medical Branch (UTMB) clinics and surrounding community, and will be screened for inclusion/exclusion criteria. Eligible patients will sign an informed written consent. At their baseline visit, participants will have their blood drawn, be randomized into either the study or control group, and receive their first dose of the HPV vaccine. All participants will receive compensation administered through a ClinCard following each of the 4 blood draws.