Moderna and AstraZeneca are close behind and are likely to have early data on their vaccine candidates before the end of the year. More than 150 potential vaccines are being developed and tested globally to stop the COVID-19 pandemic, with 42 in human trials, according to the World Health Organization (WHO).

(Reporting by Amruta Khandekar, Dania Nadeem, Mrinalika Roy and Vishwadha Chander in Bengaluru; editing by Ankur Banerjee, Maju Samuel, Ramakrishnan M. and Sriraj Kalluvila)