After American firm Pfizer sought approval from the drug regulator, Serum Institute of India, the world's largest vaccine maker by number of doses produced, has sought government approval for emergency use authorisation of the coronavirus vaccine that it is developing with the University of Oxford and British drugmaker AstraZeneca. Serum Institute of India partnered with AstraZeneca to conduct trials on its Covishield vaccine in India. Adar Poonawala tweeted, As promised, before the end of 2020, @SerumInstIndia has applied for emergency use authorisation for the first made-in-India vaccine, COVISHIELD.