Billionaire philanthropist Bill Gates has showered rich praise on companies from emerging nations, including India, for donning the role of 'hidden vaccine heroes' and driving down their cost to about $1 per dose in the global fight to protect kids from deadly diseases…The increased competition and new manufacturing approaches created by these firms have made it possible to protect a child against eight major diseases…Despite all the progress, more must be done to target the 22 million children, mainly in the poorest countries, who do not have access to lifesaving vaccines, Mr Gates said. [Refers to Bharat Biotech, Biological E, Bio-Manguinhos, China National Biotec Group, Serum Institute of India (part of Poonawalla Group), Microsoft]