Six-year antibody response after one dose of the 9‑valent HPV vaccine in students
Persistence of Immune Response Six Years After One Dose of 9vHPV Vaccine Among Male and Female Students
We will test whether one dose of the 9‑valent (9vHPV) vaccine given to 9–11‑year‑old students in 2019–2020 still produces antibodies six years later.
Quick facts
| Phase | Phase 4 |
|---|---|
| Study type | Interventional |
| Enrollment | 300 (estimated) |
| Ages | 15 Years to 17 Years |
| Sex | All |
| Sponsor | Canadian Immunization Research Network Research network |
| Locations | 1 site (Québec, Quebec) |
| Trial ID | NCT07156084 on ClinicalTrials.gov |
What this trial studies
Researchers at CHU de Québec‑Université Laval will recruit about 300 youth (approximately 150 girls and 150 boys) who received a single 9vHPV dose in Grade 4 during 2019–2020. Participants will complete a brief questionnaire and provide a blood sample to measure HPV antibody levels roughly six years after vaccination. Eligible participants must have received exactly one 9vHPV dose at ages 9–11 and be immunocompetent; anyone who received additional HPV doses or is immunosuppressed will be excluded. The results will describe persistence of antibody responses at an age when many begin sexual activity and help inform local and national vaccination policy.
Who should consider this trial
Good fit: Immunocompetent youth who received exactly one 9vHPV dose at ages 9–11 during the 2019–2020 Grade 4 school program and can consent are ideal candidates.
Not a fit: Individuals who received additional HPV vaccine doses, are immunosuppressed, or were vaccinated outside the 2019–2020 Grade 4 program are unlikely to benefit from or be eligible for this study.
Why it matters
Potential benefit: If antibody levels remain detectable six years after one dose, this could support that a single 9vHPV dose provides lasting immune protection and simplify vaccination schedules.
How similar studies have performed: Observational studies and policy reviews have shown encouraging immune responses and real-world protection after single-dose HPV schedules, prompting WHO and Canadian recommendations, but long-term data—especially in boys—remain limited.
Eligibility criteria
Show full inclusion / exclusion criteria
Inclusion Criteria: * Have received a single dose of 9vHPV vaccine at ages 9-11 during the school year 2019-2020; * Not have received any other HPV vaccine doses; * Be able to consent to the study. Exclusion Criteria: * Immunosuppressed (at recruitment or when immunized).
Where this trial is running
Québec, Quebec
- Centre de recherche du CHU de Québec-Université Laval — Québec, Quebec, Canada (Recruiting)
Study contacts
- Principal investigator: Chantal Sauvageau, MD — INSPQ and Laval University
- Study coordinator: Chantal Sauvageau, MD
- Email: chantal.sauvageau@inspq.qc.ca
- Phone: 418650-5115
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.