Total Severity Score (TSS) comparison in vaccinated and unvaccinated patients during the fourth wave (December 2021 - January 2022) of COVID-19 in Italy

OBJECTIVE: This study aims at comparing the severity score assessed using high-resolution computed tomography (HRCT) in vaccinated and unvaccinated COVID-19 patients. PATIENTS AND METHODS: From the first of December 2021 to first of February 2022, we conducted a single-center retrospective analysis on COVID-19 patients who accessed ED services. The hospital in question is a level II facility with a catchment area of around 200,000 people. According to the Italian recommendations, patients were divided into four groups based on the CT score of Micheal Chung. The sum of acute inflammatory lung lesions involving each lobe was scored as 1 (0-25%), 2 (26-50%), 3 (51-75%) or 4 (76-100%) on a visual quantitative assessment of CT. The total severity score (TSS) was determined by summing the five lobe scores. RESULTS: The study included 134 patients divided into two groups: 67 vaccinated and 67 unvaccinated people. 53 people had incomplete (single dose/double dose) immunization, while 14 people completed the vaccination cycle. It was discovered that the mean CT severity score was lower in fully vaccinated patients compared to partially vaccinated or unvaccinated patients. The mean CT score was significantly lower in fully vaccinated patients aged 60 compared to older patients. The mean CT score was higher in unvaccinated patients compared to fully vaccinated patients. CONCLUSIONS: Individuals who received three doses of COVID-19 vaccination had lower CT severity scores than patients who received only one dose of vaccine or no vaccines at all.