Researchers around the world are developing more than 145 vaccines against the novel coronavirus, and some 21 vaccines are conducting or about to start human trials. India now has two coronavirus vaccines set for human trials -- Bharat Biotech and Zydus Cadila. But just developing the vaccine is not the only challenge. The challenge after that is to ensure its production can be scaled up and supplied to everyone in an equitable way. Dr Jerome Kim, Director General of the International Vaccine Institute tells NDTV how he is hopeful of a vaccine by the end of the year and how India will play a key role in its productio