NEW DELHI : The Drug Controller General of India’s office has approved Serum Institute of India’s application for the phase II and II clinical trials of University of Oxford’s promising covid-19 vaccine candidate ‘Covishield’, the health ministry said on Monday.The approval will make Pune-based Serum Institute the third manufacturer to conduct human trials in India after Bharat Biotech International Ltd’s ‘Covaxin’ and Zydus Cadila’s ZyCoV-D got approvals for the first two phases last month.The approval from the DCGI comes after an expert committee last week recommended that the company be allowed to conduct trials after studying the revised proposal the firm for a 1,600-patient trial, according to sources in the know.The Subject Expert.