Uttar Pradesh, with a massive challenge of vaccinating one of the most populated states in India, began the COVID-19 vaccination drive today after PM Modi launched the nation-wide programme this morning. The vaccination started at 317 centres across 75 districts and 9 lakh frontline health workers were vaccinated on the first day, with anganwadi workers being given priority. NDTV's Alok Pandey and Rajesh Gupta report on challenges facing the state in its vaccination drive.