India is all set to begin the world’s largest Covid-19 vaccination drive on Saturday. Prime Minister Narendra Modi will flag-off the first phase of the drive at 10:30 am today via video conference. During the first phase of the inoculation drive about three crore healthcare and frontline workers will be vaccinated. The cost incurred during the first phase of vaccination will be borne by the Centre, Union Health Minister Harsh Vardhan said earlier.