Persistence of Immune Response Six Years After One Dose of 9vHPV Vaccine Among Male and Female Students

Condition(s) studied

Investigational drug(s) / intervention(s)

HPV nonavalent vaccine (Gardasil-9): One dose HPV nonavalent vaccine

Study summary

Since the 2019-2020 school year, the province of Quebec (Canada) has been administering one dose of nonavalent (9vHPV) vaccine to students of all genders in Grade 4 of elementary school through the school-based program.

Little data on the immunogenicity (antibody production) and long-term efficacy of a single dose of the vaccine are available, particularly in boys.

The primary objective of this study is to assess the persistence of HPV antibodies six years after the administration of a single dose of the 9vHPV vaccine to students aged 9 to 11 years in Grade 4 in 2019-2020.

The study will be conducted at the CHU de Québec-Université Laval research center.

Recruitment is conducted through school service centers in the Quebec City region. Youth who received only a single dose of the 9vHPV vaccine at the ages of 9-11 in 2019-2020 will be eligible to participate.

Approximately 300 youth will take part in this study: 150 girls and 150 boys.

Participants will have to answer few questions about their health to ensure their eligibility for the study. For eligible participants consenting to participate a 10 ml (\<1 tablespoon) blood sample will be taken.

Eligibility

Primary outcome measure(s)

• Detectable antibodies — At recruitment (6 years post-one HPV vaccine dose)
  Proportion of participants with detectable antibodies
• Geometric mean concentrations — At recruitment (6 years post-one HPV vaccine dose)
  Geometric mean concentrations of antibodies

Trial sites (1)

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