High Resolution Computed Tomography (HRCT) Chest Assessment of Vaccinated and Non-Vaccinated COVID-19 Patients in a Tertiary Care Centre

Background: Mass vaccination is recognized as the most effective preventive measure to halt transmission of COVID-19 infection. This study was undertaken to compare the clinical and radiological profiles of COVID-19 patients in vaccinated and nonvaccinated patients. Materials and Methods: This retrospective study was conducted in the Department of Radiodiagnosis, GIMS, GADAG. The clinical and chest imaging data of 150 RT-PCR positive patients who had undergone a standardized HRCT chest imaging were analyzed. CT severity scoring was given for each of the 5 lobes, and the CT severity Index (CTSI) score was calculated as the sum of each individual lobar score in both vaccinated and non-vaccinated patients. Patients were further categorized into mild, moderate and sever based on CTSI score, and were compared between the two study groups. Results: Majority of patients were male in both Vaccinated (58%) and non-vaccinated (55%) groups. In our study, out of 150 patients, 50 patients were vaccinated and 100 patients were nonvaccinated for COVID-19. Of 50 vaccinated patients, 42% of patients had received single dose of vaccine, while 58% had received double dose of COVID-19 vaccine. Lung involvement on HRCT was observed in 30% of vaccinated patients, and 95% of non-vaccinated patients. In Vaccinated group, mild (20%) lung involvement was observed in most of the patients, while in non-vaccinated group, majority of patients had moderate (60%) lung involvement. Conclusion: This study concluded that patients vaccinated against COVID-19 demonstrates less severe lung involvement than non-vaccinated patients. Thus, HRCT can be used as an accurate means for determining the severity of COVID-19-related pneumonia.