Effect of COVID 19 vaccination on the CT severity score for SARS CoV2 pneumonia- an experience from the initial wave.

The severe acute respiratory syndrome coronavirus 2 pandemic started in the December of 2019 at China. The second wave of the pandemic in India peaked between April-May 2021. In order to reduce the transmission and infectivity of the virus several vaccines were approved for emergent use. Studies have shown the effectiveness of vaccination in reducing the clinical severity of infection by the corona virus. In this study we aim to assess the effect of vaccination on the computed tomography severity score (CTSS). The study included 140 patients who tested positive for COVID 19 on RT PCR or rapid antigen test. Seventy of these patients had received at least one dose of vaccination and 70 patients were unvaccinated.  CT scan of the chest was done for all patients and a CTSS ranging from 0 to 25 was assigned depending on the extent of lobar involvement. We found that a higher percentage (72.86%) of unvaccinated patients had severe disease compared to the vaccinated group (38.57%), 5.71% of unvaccinated patients had mild disease compared to 30% of vaccinated patients. The difference between the two groups was found to be statistically significant. On comparing the CTSS of patients with and without vaccination in our study, we found a significant reduction in the severity scores in the vaccinated group. Through this study the vaccine’s efficacy could be validated objectively. This article aims to emphasize the role of vaccination in our fight against the pandemic caused by the corona virus.