Clinical Science | Covid-19

A Kline, L Trinh, M Hussein, R Elshazli, A Attia, M Fawzy, E Toraih, M Killackey, J Duchesne, E Kandil

ePoster Presenter: Adam Kline BS, Tulane School of Medicine

Background: The COVID-19 pandemic reached its precipice as the 2019-2020 influenza season neared its end. The annual influenza vaccine has prevented the spread of flu and improved outcomes in patients hospitalized with flu. However, limited data exists on the potential benefits of the flu vaccine and COVID-19 outcomes.

Objectives: The purpose of this study is to evaluate the impact of annual vaccination on the disease course and outcomes of COVID-19 in a cohort of COVID-19-positive patients.

Methods: This multi-center, retrospective study was completed by obtaining data from COVID-19 positive patients, who had been admitted from March 20, 2020 to May 10, 2020. Demographics, underlying comorbidities, clinical presentation, laboratory values, and outcome data was collected. Statistical analysis was used to compare data between vaccinated and unvaccinated patients. Multiple regression analysis was performed for all outcomes.

Results: 149 COVID-19 positive patients were included in our study. 98 (65.8%) received at least a single annual flu shot in the last year and 51 (34.2%) were never vaccinated against the annual flu. On presentation, vaccinated patients were more likely to present with gastrointestinal symptoms such as nausea, vomiting, and diarrhea (p<0.05). There were no statistically significant differences between groups in laboratory findings, or clinical outcomes. After adjustment by multivariate analysis, receiving 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: The benefits of the influenza vaccine for preventing disease spread and reducing morbidity in influenza patients are well-established. However, our study showed no differences in key outcomes for hospitalized COVID-19 patients who received their annual influenza vaccination. The 2020-2021 influenza vaccine is recommended for all individuals without a contraindication and should be prospectively studied to evaluate any impact on overall COVID-19 disease burden.