Hospital consequences of COVID-19 vaccinated and unvaccinated patients among the Iranian adult population

Introduction:Coronavirus disease 2019 is an emerging respiratory infectious disease caused by a strain of the coronavirus family.Vaccination is one of the main ways to control this disease.This study was conducted to investigate the severity of pulmonary involvement and some clinical outcomes in vaccinated and unvaccinated COVID-19 patients. Materials and Methods:This retrospective study was conducted between December 2021 and May 2022 with 200 patients in two groups.Sampling was done as available, and patients with COVID-19 admitted to the hospital were investigated.Data analysis was performed using SPSS V.16, applying Mann-Whitney U, and chi-square tests were used at a 5% significance level. Results:The average age of the studied patients was 59.2 (17) years; the most common pattern of lung involvement in this study was the GGO pattern.According to the report in the documents, 45 people in the vaccinated group and 9 people in the unvaccinated group did not have any lung involvement in CT, and the observed difference was statistically significant (P = 0.001).In the oxygen saturation percentage, the lowest level (75%) was observed in the unvaccinated group.Also, the difference in average hospitalization days between the two groups was statistically significant (P = 0.050). Conclusion:The results of this study showed that the COVID-19 vaccine can effectively reduce the extent and severity of lung involvement and the need for supplemental oxygen in vaccinated patients.