Background The coronavirus disease-2019 (COVID-19) pandemic devastated public health worldwide, including India. COVID-19 vaccines and their boosters are life-saving developments that have helped prevent and control the spread of COVID-19. We conducted this study to assess the coverage of the booster dose in an Indian population (the third dose of the COVID-19 vaccine in India is referred to as the booster or precautionary dose), record the reasons for not taking the booster dose, and determine the effectiveness of the booster. The levels of adherence to COVID-19 precautionary behavior was als...