LAUSR

AIM OF THE STUDY The impact of annual flu vaccination on the COVID-19 patients' clinical course and the outcome was tested. METHODS A total of 149 COVID-19 positive patients admitted from March 20 to May 10, 2020, were retrospectively enrolled. RESULTS Ninety-eight (65.8%) patients received at least a single annual flu shot in the last year, and 51 (34.2%) were never vaccinated. On presentation, vaccinated patients were more likely to present with gastrointestinal symptoms (p<0.05). There were no significant differences between study groups in laboratory findings or clinical outcomes. In multivariate analysis, receiving the annual shot did not influence risk of intensive care unit admission (OR=1.17, 95%CI=0.50-2.72, p=0.72), intubation (OR=1.40, 95%CI=0.60-3.23, p=0.43), complications (OR=1.08, 95%CI=0.52-2.26, p=0.83), or mortality (OR=1.29, 95%CI=0.31-5.29, p=0.73). CONCLUSION Although the benefits of the influenza vaccine for preventing disease and reducing morbidity in influenza patients are well-established, no differences in outcomes for hospitalized COVID-19 patients who received their annual influenza vaccination versus the non-vaccinated cohort were evident. There is a need for future meta-analyses, including randomized controlled studies in which the number of cases is increased to validate these findings.