Prime Minister Narendra Modi on Friday launched a customised crash course programme that aims to skill and upskill over one lakh "Covid warriors" across the country. <br /> <br />Speaking on the occasion, Modi urged the people to remain cautious, stressing that the virus is "still amongst us" and the possibility of it mutating is also there. <br /> <br />He also said the central government is committed to provide Covid vaccination free to everyone, starting June 21.