The Influenza Season: A Comparative Study of Admission Rates and Influenza Vaccinations in the Kingdom of Bahrain.

Background and objective Influenza remains a significant global public health challenge, contributing to seasonal rises in healthcare utilization, hospital admissions, and morbidity. Vaccination is recognized as the most effective preventive strategy against influenza infection. This study aimed to examine the association between influenza vaccination status and key clinical outcomes, including hospital admission rates and length of hospital stay, during the 2024-2025 influenza season in the Kingdom of Bahrain. Methods A retrospective analysis was conducted involving 5,033 patients who underwent polymerase chain reaction (PCR) testing for influenza in 2024. Patients were categorized into three groups: vaccinated during the current flu season (September 2024 to April 2025), vaccinated in previous seasons, and unvaccinated. Data were extracted from the national I-SEHA electronic health records system. Admission rates, length of hospital stay, and age distribution were analyzed across the groups. Results Among the study population, 237 individuals (4.7%) were vaccinated in the current flu season, 1,007 (20%) in prior seasons, and 3,789 (75.3%) remained unvaccinated. Of all hospital admissions, 4.4% were from the currently vaccinated group, 20.3% from those vaccinated in previous seasons, and 75.3% from unvaccinated individuals. The mean length of hospital stay was shortest in the current-season vaccinated group (7.1 days) compared to those vaccinated previously (10.3 days) and the unvaccinated group (9.4 days). Conclusions Timely influenza vaccination during the current season was associated with fewer hospital admissions and shorter hospital stays. These findings highlight the importance of seasonal vaccination campaigns and the need for continued public health efforts to promote annual influenza vaccination in order to reduce disease burden and healthcare strain.