E3337. Various COVID-19 Vaccines: What is the Best Among Them?
  1. Clarisse Dianne Cayetano; Philippine General Hospital
  2. Rovi Niño Samedra; Philippine General Hospital
The primary purpose of the study is to identify the roles of the chest CT imaging and vaccination in the COVID-19 pandemic. This retrospective study also aimed to establish the association between the chest CT total severity scores (CT-TSS) of adult COVID-19 positive patients admitted at Philippine General Hospital (PGH) and their vaccination status; compare the different COVID-19 vaccine brands administered to the patients based on their chest CT-TSS; and determine the incidence and characteristics of chest CT scan findings of COVID-19 vaccine breakthrough cases.

Materials and Methods:
We reviewed demographic data, COVID-19 vaccination records and chest CT scans of adult patients (> 18 years of age) who were confirmed to have COVID-19 via RT-PCR and were admitted at PGH from March 2021 to December 2022 was done. The chest CT-TSS by Kunwei et. al was used, due to its high specificity, to assess the degree of affectation of the lung parenchyma due to COVID-19. The TSS lung involvement was categorized as severe disease if the total score was more than or equal to 7.5.

Results showed that chest CT severity scores and severity score categories have a strong and significant association with the vaccination status of COVID-19 patients (<em>p</em> < 0.001). Based on the median score of the patient’s chest CT-TSS and the incidence of severe COVID-19 infections, Sinovac (whole inactivated virus vaccine) showed the highest chest CT-TSS score (10) and incidence of severe COVID-19 infections (52.3%) among the study population while Moderna (messenger RNA vaccine) showed the least number (median CT-TSS of 4 and 4.65% severe disease). Results showed that there is a moderately significant association between the first COVID-19 vaccination brands and the severity score category of the patients (<em>p</em> = 0.048). COVID-19 breakthrough infections (104/341 patients) were also identified in this study and most of them received the primary series of Sinovac (51.33%). The three most predominant chest CT scan findings among the breakthrough cases, in decreasing order, are ground glass densities (25.82%), consolidation (18.96%), and crazy paving pattern (17.31%).

Completion of the primary vaccine series and administration of booster shots are relevant actions for the management and control of the COVID-19 infection. In light of the different COVID-19 vaccine brands, the efficacy of the each vaccine should also be considered. This study has provided significant evidence of vaccine efficacy in reducing disease severity in patients with COVID-19 based on their chest CT-TSS. Furthermore, breakthrough infections still emerge despite the efficacy of the COVID-19 vaccinations. But the majority of these patients present with a milder form of disease compared to unvaccinated patients. It is crucial to comprehend vaccination breakthrough infections to effectively combat continuing COVID-19 infections and prevent possible future outbreaks.