Impact of COVID-19 vaccinations in India: a state-wise analysis

Article Type

Research Article

Publication Title

BMC Public Health

Abstract

Background: Ever since the emergence of COVID-19 and its consequent spread across continents, engulfing both advanced and developing nations, COVID-19 vaccine was considered to be the main weapon to curb the spread of the virus. The COVID-19 vaccination program in India started after the first wave of infections (March – December 2020) had almost subsided. Objective: In this work, the objective is to perform a state-wise analysis to assess the impact of vaccination in slowing down the spread of infections during the second COVID-19 wave (February – October 2021) in India. The prediction accuracy of the proposed model with the optimal lag length (in days) after including the impact of vaccination is evaluated and compared with a model without it. A total of 21 states are chosen for the analysis encompassing 97% of the Indian population. Methods: We use the generalized Gompertz curve to study the COVID-19 outbreak. The generalized Gompertz model is then further modified to study the impact of vaccination to slow down the spread of COVID-19. The modified model considers the cumulative proportion of individuals having the first COVID-19 vaccine shot in each state as the explanatory variable. Results: By incorporating the impact of vaccination in the Generalized Gompertz Curves, it is seen that the visible impact of the first dose of the vaccination is observed after a lag of 20 days with 16 out of the 21 states showing the impact of vaccines in curbing the spread of COVID-19. However, in states like Telangana, West Bengal, Tamil Nadu, Rajasthan, and Kerala, we do not conclusively observe the impact of vaccination during the study period. Conclusions: Using only COVID-19 infection cases and the vaccination data in the proposed model, we conclude that overall, the vaccination program effectively curbed the spread of COVID-19 in India.

DOI

10.1186/s12889-025-21401-7

Publication Date

12-1-2025

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