Determinants of influenza vaccination in a French primary care population in the post-COVID-19 era.
BACKGROUND Influenza vaccination coverage in France remains suboptimal, with variability across population groups. We assessed demographic and behavioral determinants of influenza vaccination in the post-COVID-19 period among a primary care population in the Haute-Vienne department (Nouvelle-Aquitaine, France). METHODS We conducted a cross-sectional survey using an anonymous, self-administered questionnaire distributed to adults attending five general-practice sites between May and July 2023. The primary outcome was receipt of the 2022-2023 influenza vaccine. Candidate determinants included age, sex, municipality size, socio-professional category, eligibility criteria (age ≥ 65 years, healthcare-worker status, chronic conditions, or pregnancy), prior influenza vaccination, number of COVID-19 vaccine doses received, and self-reported history of influenza infection. Associations were examined using chi-square tests, Cochran-Armitage trend tests, and univariate logistic regression. Two multivariable logistic regression models were then constructed: a demographic model including age, sex, municipality size, socio-professional category, and the presence of any comorbidity or pregnancy, and a behavioral model including prior influenza vaccination and COVID-19 vaccination status (≥ 3 doses vs. ≤ 2 doses). Adjusted results were expressed as adjusted odds ratios (aOR) with 95% confidence intervals (95% CI). RESULTS Among the 800 questionnaires distributed, 432 were returned (participation rate: 54%). Overall, 75.9% of participants met at least one eligibility criterion for influenza vaccination. Influenza vaccination coverage for the 2022-2023 season was 58.3% and differed by municipality size (38.8% in areas with fewer than 5,000 inhabitants; 59.2% in those with 5,000-10,000; and 64.3% in those with more than 10,000, p = 0.0003) and increased with the regularity of prior influenza vaccination (6.7% among never vaccinated, 55.9% among occasional, and 96.6% among annually vaccinated, p < 0.0001). Coverage was also associated with the number of COVID-19 vaccine doses received (p < 0.0001). In the demographic model, age ≥ 65 years was associated with higher vaccination uptake (aOR 8.55, 95% CI 1.88-61.73, p = 0.012), whereas other demographic variables were not independently associated with vaccination uptake. In the behavioral model, prior influenza vaccination was strongly associated with vaccination uptake (aOR 16.20, 95% CI 7.21-36.41 for occasional vs. never and aOR 331.21, 95% CI 122.57-894.99 for annual vs. never; both p < 0.001). Receipt of ≥ 3 COVID-19 vaccine doses was also independently associated with vaccination uptake (aOR 2.64, 95% CI 1.01-6.89, p = 0.047). CONCLUSIONS In this primary care survey, influenza vaccination during the 2022-2023 season was primarily associated with prior influenza vaccination history, suggesting persistence of vaccination practices over time. Age ≥ 65 years and receipt of ≥ 3 COVID-19 vaccine doses were also independently associated with vaccination uptake, although to a lesser extent. Targeted strategies that reinforce continuity (annual reminders, vaccination offers during routine visits, and co-administration options) and encourage initiation among previously unvaccinated adults could help improve coverage. TRIAL REGISTRATION Not applicable.