Clinical trials are extremely important to ensure safety, efficacy and efficiency levels of a vaccine, says K Sujatha Rao, former secretary in the Ministry of Health and Family welfare. The recent directions from Indian Council of Medical Research (ICMR) to all 12 trial sites for the Covid-19 vaccine candidate, Covaxin, to complete clinical trials by August 15, has kicked up a row. In an interview with Outlook's Preetha Nair, Rao warns that if norms are not followed, a bad vaccine can be ineffective and such reputation will end in people not buying it.