Assessing a local vaccination initiative: Eight years of "Immuniser Lyon" in France.

Abstract

"Immuniser Lyon" (IL) is a French city-level initiative launched in 2015 to promote vaccination through coordinated, locally tailored actions. The objective of this study is to describe and compare temporal trends in vaccine coverage for HPV and influenza in the Rhône area versus the neighboring Auvergne-Rhône-Alpes (ARA) region, and to explore whether observed patterns are consistent with a potential contribution of the IL initiative. A comparative analysis of vaccine coverage was performed for HPV (2010-2022) and influenza (2016-2020) between different areas within the Auvergne-Rhône-Alpes (ARA) region versus the ARA region, using binomial log-linear models. HPV vaccine coverage in Rhône and ARA followed similar patterns, increasing from 2015 to 2022 after a nationwide decline. For influenza, vaccine coverage among adults aged ≥65 was significantly higher in Lyon in 2020 (64.5%) than in the rest of ARA (59.2%, OR=1.25, 95% CI [1.24-1.26], p < 0.001). While HPV trends reflected broader national dynamics, the observed pattern may be consistent with a potential contribution of IL to the accelerated uptake of influenza vaccines in older adults. These findings highlight the potential of sustained local action to complement national immunization strategies.