Visualizing the efficacy of vaccination in different Indian states: a comparative account with other countries

Efficacy of the vaccination program for COVID-19 pandemic caused by SARS-CoV-2 (Severe Acute Respiratory Syndrome-CoronaVirus-2) was analyzed. The data for number of cases and vaccination, obtained from government websites from 1st January, 2020 to 10th October, 2021 for India, USA, United Kingdom, Italy, South Africa and states West Bengal, Delhi, Maharashtra, Kerala and Tamil Nadu. Modified Poisson prediction models were developed using SPSS to predict the number of cases with and without vaccination as predictor to catalogue the efficacy of vaccination. In the prediction model where vaccination was used as a predictor, the downward trend of predicted value matched with actual value, falling within the 95% confidence interval. However, individual peaks of waves were not observed clearly for the predicted values. Vaccination within the population was observed to be very critical in controlling the pandemic progression with all countries showing decrease in daily case counts as more people in the population got vaccinated. In India, owing to the huge population, more vaccination is needed for the predicted cases to fall lower.