INTRODUCTION : COVID vaccination was started in India on 16-01-21. Initially high risk groups were given priority. Since May, 2021, all adults above 18 years started receiving covid vaccination. Covishield (AZD1222) and Covaxin were used in Tamil Nadu. The study was conducted to determine the effectiveness of vaccine against fatality.
METHOD : We conducted a matched case control study based on secondary data of Kanyakumari District, Tamil Nadu. Case was any death in a COVID 19 positive individual of age more than 18 years which got documented as due to COVID illness. We selected two controls for each case matching age, sex and date of positivity. We had 94 cases and 188 controls. We calculated Odds ratio, adjusted odds ratio for protection by any COVID vaccine/ covishield.
RESULTS : Effectiveness against fatality due to covid 19 with two doses of any covid vaccine was 90% after adjusting for comorbidities; for covishield was 98%. Effectiveness against fatality of single dose of any covid vaccine was 77% and that of covishield 76%.
CONCLUSION : Two doses of any covid vaccine/ covishield could be protective against death due to covid illness for nearly all adults irrespective of their age, gender, common non communicable diseases and virulence of covid virus; even single dose could be protective for majority.