A Phase 4 interventional study of Gardasil 9 2 dose regimen and Gardasil 9 3 dose regimen in HPV Infection, sponsored by Boston Medical Center. Active, not recruiting at 1 site in United States. Open to female participants aged 16 Years to 45 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-04-29.
Sponsored by Boston Medical Center · Phase 4, Interventional, and Basic science
The goal of this study is to explore and evaluate whether a 2-dose schedule of Gardasil 9 among young and mid-adult women 16-45 years of age is generally safe and immunogenic, with an antibody response that is not inferior to that observed of a 3-dose schedule of Gardasil 9 among women aged 16-26 years old. The investigators thought that having a 2-dose vaccination regimen for individuals 16 to 45 would provide a more robust dataset than those of 27 to 45 years old.
The investigators will identify potential eligible subjects from the Boston Medical Center (BMC) Clinical Data Warehouse from the following BMC clinics: Pediatrics, Adolescent Medicine, Family Medicine, Obstetric/ Gynecology (OB/GYN), and Women's Health/Adult Primary Care. The research team will mail a recruitment opt-out letter signed by the principal investigator to the participant along with a study flyer. The recruitment letter will inform the participant that a research member may contact them via phone within two week to provide more information regarding the study.
Participants opting-in will be called and interviewed with the study recruitment script and eligibility will be determined. Eligible participants who agree to participate (in-person or over the phone), will be scheduled to come to the Boston University (BU) General Clinical Research Unit (GCRU) to complete the consent process. At the baseline visit participants will be assigned into the appropriate group (control vs. intervention) based on their age.
495 studies on the registry are indexed under Papillomavirus Infections; 125 are open to participants now.
This study's enrollment of 352 is above the median of 202 across 332 interventional studies indexed under Papillomavirus Infections.
Browse Papillomavirus Infections studies →Boston Medical Center is the lead sponsor of 314 studies on the registry; 34 are open to participants now.
Of its 34 completed or terminated interventional studies of FDA-regulated products, 28 (82%) have results posted.
Counted across the registry records on this site, refreshed daily.
Exclusion Criteria:
240 eligible women will receive a 2-dose regimen of Gardasil 9 at (0 and 6 months, followed by a rescue 3rd dose at month 12)
Drug: Gardasil 9 2 dose regimen · Drug: Gardasil 9 rescue dose
120 eligible women will receive the standard 3-dose regimen of Gardasil 9 at (0, 2, 6 months)
Drug: Gardasil 9 3 dose regimen
a 2-dose regimen of Gardasil 9 at 0 and 6 months
Also known as: Human Papillomavirus 9-valent Vaccine, Recombinant
standard 3-dose regimen of Gardasil 9 at 0, 2, 6 months
Also known as: Human Papillomavirus 9-valent Vaccine, Recombinant
A rescue dose of Gardasil 9 will be given at 12 months
Also known as: Human Papillomavirus 9-valent Vaccine, Recombinant
Change in immunogenicity of Gardasil 9
Immunogenicity will be measured by serum antibodies assessed by ELISA to the nine HPV types (anti-HPV 6/11/16/18/31/33/45/ 52/58 where positive anti-HPV serum levels are defined as \>30, \>16, \>20, \>24, \>10, \>8, \>8, \>8, or \>8 milli Merck units (mMU)/mL respectively).
Time frame: baseline and 7 months
Change in geometric mean titers ratios
The geometric mean titers (GMT) ratios will be determined by a post-vaccination geometric mean titer (GMT) ratio with a pre-stated analysis of variance model (95% Confidence Interval lower bound \>0.5).
Time frame: baseline and 7 months
Number of participants with HPV seropositivity at day 1
The number of participant who test positive in mili Unit (nMU) which will be will be defined as anti-HPV 6/11/16/18/31/33/45/ 52/58 positive if her anti-HPV serum level is \>30, \>16, \>20, \>24, \>10, \>8, \>8, \>8, or \>8 milli Merck units (mMU)/mL for the 9 types, respectively. The serum testing will be under the direction of Merck research lab.
Time frame: day 1
Number of participants with HPV seropositivity at month 7
The number of participant who test positive in mili Unit (nMU) which will be will be defined as anti-HPV 6/11/16/18/31/33/45/ 52/58 positive if her anti-HPV serum level is \>30, \>16, \>20, \>24, \>10, \>8, \>8, \>8, or \>8 milli Merck units (mMU)/mL for the 9 types, respectively. The serum testing will be under the direction of Merck research lab.
Time frame: month 7
Plan to share: No
This study is active, not recruiting, as verified in Apr 2026. You cannot join it, but the record below documents what was studied.
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