Patterns and Predictors of Influenza Vaccination Uptake Among Healthcare Personnel in Kuwait: A Nationwide Multi-Season Study

Background/Objectives: Healthcare personnel (HP) are a priority group for seasonal influenza vaccination due to their increased occupational exposure and potential to transmit influenza in healthcare settings. This study examined patterns and factors associated with in-season influenza vaccination uptake among HP in Kuwait. Methods: A nationwide observational study was conducted using Ministry of Health (MOH) administrative records covering the 2022/2023 through 2024/2025 influenza seasons. A person–season dataset was constructed, comprising one observation per HP for each of the three seasons. The primary outcome was in-season influenza vaccination, defined as receipt of an influenza vaccine between September and March of a given study season. Independent variables included age, sex, nationality, governorate of residence, profession, managerial position, previous-year influenza vaccination status, and pre-season sickness absence duration (days). Generalized estimating equations (GEE) logistic regression model with an exchangeable correlation structure was used to estimate factors associated with vaccination uptake. Results: The final analytic dataset included 48,886 HP contributing 146,658 person–season observations across three influenza seasons. Overall, in-season vaccination uptake was 8.7%, and repeated vaccination across seasons was uncommon. Older age, male sex, non-Kuwaiti nationality, and being a physician were independently associated with higher odds of in-season influenza vaccination. Previous-year influenza vaccination was the strongest predictor of current-season vaccination uptake (aOR 2.01, 95% CI 1.87–2.16; p < 0.001). Compared with HP with no pre-season sickness absence, those with 1–3 pre-season sickness absence days had slightly higher adjusted odds of vaccination (aOR 1.08, 95% CI 1.03–1.14), whereas those with ≥8 days had lower adjusted odds (aOR 0.91, 95% CI 0.85–0.97). Conclusions: In-season influenza vaccination uptake among HP in Kuwait was low across three consecutive influenza seasons, with limited continuity of annual vaccination. Previous-year vaccination was the strongest predictor of current-season vaccination uptake, while the association between pre-season sickness absence and vaccination varied by absence duration. These findings support continued efforts to improve and sustain in-season influenza vaccination uptake among HP, while further research is needed to clarify the factors underlying vaccination decisions.