Effectiveness of coronavirus disease-19 vaccination on disease transmission, hospitalization, and clinical outcomes in adults in North India

Background: Covaxin and Covishield vaccines have rapidly rolled out in India to curb the pandemic. We aimed to test the hypothesis that COVID-19 vaccination is clinically effective. Methods: This study was conducted in the Department of Physiology at MGM College, Jaipur, India after approval from the Ethics Committee. Vaccinated and non-vaccinated groups were tested on disease transmission, hospitalization, and clinical outcomes. Researchers collected data using questionnaires circulated through google forms. The association between attributes was tested using the chi-squared test. The significance level was considered at 5%. Results: The vaccination significantly reduced disease transmission of COVID-19 [c2=4.51; p = 0.034]. However, no significant differences were seen in RTPCR positivity, chest CT findings, and hospitalization on vaccination. COVID-related symptoms and their severity were not statistically different between the two groups. Most elderly were vaccinated [c2=41.68; p < 0.001]. Most youths took one dose, while the elderly took two doses of the vaccine [c2=41.77; p < 0.001]. All age groups had similar severity of AEFIs [c2=13.22; p < 0.21]. The vaccination status across gender did not differ significantly. [c2=1.13; p < 0.288] Most males took two doses as compared to females [c2=6,57; p < 0.01]. Adverse effects post-immunization were more severe in females than males [c2=13.10; p < 0.001]. There was no association between the number of vaccine doses and the severity of AEFIs [c2=16.42; p = 0.06]. Conclusion: The present study concludes the beneficial effect of vaccination in reducing disease transmission. However, vaccination has no role in mitigating other COVID-related outcomes.