The centre has given 100 per cent advance to two of India's Covid vaccine manufacturers till July, senior sources in the Finance Ministry told NDTV on Monday night. The advance - calculated as ₹ 3,000 crore for the Serum Institute (which produces Covishield) and ₹ 1,000 crore for Bharat Biotech (which produces Covaxin) will ensure the two manufacturers get the funding necessary to continue, and scale up, production of vaccines, the sources said.