Covaxin, India's first indigienous vaccine for the highly infectious coronavirus, has been designed to be effective if a person takes two doses, Hyderabad-based pharmaceutical firm Bharat Biotech clarified in a statement today, stressing that the "efficacy can be determined 14 days after the second dose". The clarification came soon after Haryana Health Minister Anil Vij, who was a volunteer in the third phase of vaccine trials in his state, said he has tested positive for COVID-19. "Safety is our primary criteria in vaccine development," the pharma firm assured.