Impact of Vaccination Status on Chest CT Findings and Disease Outcomes in COVID-19 Era: A Retrospective Study

Abstract

Background: Computerized Tomography (CT) was extensively used in the COVID-19 era to confirm the diagnosis and follow the patient's response. The vaccine was rapidly introduced to break the disease chain of infection. The current study primarily aimed to examine the relationship between vaccination status and pulmonary CT findings. Moreover, it also aimed to validate the role of CT scan along with other patient criteria in predicting disease outcomes. Methods: A retrospective cohort study was conducted at the radiology department of two Iraqi hospitals in Baghdad. The study enrolled all hospitalized patients with a confirmed COVID-19 diagnosis older than 18 years old. Their data regarding demographic criteria, vaccination criteria (the status and types), and radiological CT-scan parameters (including CT finding and severity score index) were collected Results: It was found that 23 percent of COVID-19 patients were immunized. Most of the unvaccinated cases were older than 45 years and were females. There was a significant correlation between the degree and severity of lung involvement and the vaccination status (p < 0.001). The worst radiological sign for severity was the ground glass appearance. The vaccine type showed significant changes in chest CT. Pfizer had the worst severity score, followed by Sinopharm in vaccinated cases. The overall mortality was 4.5%. Moreover, the vaccine significantly reduced mortality among vaccinated vs. non-vaccinated cases (p = 0.03). By logistic regression, the CT score reliably predicted mortality with an odds ratio of 1.31 (1.18 to 1.45; p < 0.001). Conclusion: Vaccines were found to be significantly effective in protecting vaccinated people against severe infection and limiting lung injury, as evidenced by CT scores. Vaccines had a trend effect on reducing mortality. Moreover, CT scores were reliable in predicting the disease outcome.