Mpact of COVID-19 Vaccines on Mortality Rates among Adult COVID-19 Patients

Abstract

Introduction: The Coronavirus Disease 2019 (COVID-19) pandemic has been a public health concern since 2019. Multiple strategies have been implemented to flatten the curve of cases, including isolating active cases, contact tracing, quarantines, lockdowns, hand hygiene, face mask usage, and sanitisation. Vaccination has been used as a tool to reduce morbidity and mortality due to COVID-19. Aim: To analyse the impact of COVID-19 vaccines on mortality rates among COVID-19 patients, with a secondary objective of studying the association between age, time since vaccination, and mortality rates. Materials and Methods: The present cohort study was conducted in the Department of Forsenic Medicine at All India Institute of Medical Sciences (AIIMS), Nagpur, Maharashtra,India, with a sample size of 60 cases, out of which 30 were included. Data was collected over a six month period from January 1, 2022, to June 30, 2022. The study included adult COVID-19 patients who were admitted to AIIMS Nagpur and subsequently died. Data on vaccine type, dose, and time since vaccination were also collected. Results: The mean age of patients was 53 years. Of the patients, 63.3% (n=57) were males and 36.6% (n=33) were females. Among the patients, 60% were vaccinated, while 40% were unvaccinated. Among the vaccinated patients, 14.8% received Covaxin, while 85.1% received Covishield. Regarding the vaccination dosage, 9.2% of the patients received a single dose, while 90.7% received two doses. All the patients who survived COVID-19 had been vaccinated for more than one month. Conclusion: Vaccination resulted in a 93.1% reduction in the odds of death among vaccinated patients. Among the unvaccinated patients, 80% died due to COVID-19. After adjusting for age and co-morbidities, vaccination was found to be independently associated with a lower risk of mortality (p<0.001). Furthermore, 73.3% of the deceased cases had comorbidities (p<0.001). The study demonstrates the protective effect of vaccination with either Covishield or Covaxin, which should hopefully address any misconceptions among the general public.