Covaxin, bharat biotech, sec, covid 19, bharat biotech s covaxin, india, DCGI, Covaxin for emergency use in age group between 6-12 years, CDSCO, Hyderabad, Zydus Healthcare, Bharat Biotech, National Technical Advisory Group on Immunisation, Astra Zeneca vaccine, Covishield, Bharat Biotech, india