Madhya Pradesh Chief Minister Shivraj Singh Chouhan said that both Covaxin and Covishield have been properly tested. He said, “Our scientists have tested them on all parameters and only then it has been decided to use them. Both the vaccines are safe and have no difference. Both of them will build immunity and antibodies.” “But the antibodies will not develop immediately after vaccination. The second dose will be administered 28 days after the first dose and 14 days after it the antibodies will develop. Two doses are necessary,” he added.