One-year impact on HPV vaccination coverage of a school- and primary care-based intervention: the PrevHPV cluster randomised trial.

Human papillomavirus (HPV) vaccine coverage (VC) remains suboptimal in many countries. The PrevHPV national research programme aimed to codevelop and evaluate a three-component intervention including: 'education and motivation' of adolescents, 'at-school vaccination', 'general practitioners (GPs)' training'. We assessed its impact on VC at one year through a cluster randomized trial (July 2021-April 2022) conducted in French municipalities (clusters) receiving 0, 1, 2, or 3 components. The outcomes (≥ 1-dose and full HPV VC at one year among 11-14-year-olds) were estimated using data from the national health reimbursement database and data collected during the trial. We performed intention-to-treat and post-hoc analysis adjusted for the dose of intervention using cluster-level linear models. Ninety-one municipalities were included. 'At-school vaccination' significantly increased ≥ 1-dose VC, in both intention-to-treat (+ 2.85 percentage points (pp), 95%CI = 0.62 to 5.09) and post-hoc analysis (+ 4.60 pp, 95%CI = 1.79 to 7.41). No significant effects were found for the other components. Results were similar for full VC. 'At-school vaccination' significantly increased VC only in municipalities with the lowest access to GPs. School-based vaccination was effective in increasing HPV VC in the medium term and may reduce VC healthcare access-driven territorial disparities. Challenges remain in parental engagement and consent for vaccination at school.Trial registration: Clinicaltrials.gov, NCT04945655. Registered 30 June 2021.