While American doctor and epidemic expert Eric Feigl-Ding expressed reservations about the efficacy of Delta variant vaccines. He asserted that AstraZeneca's vaccine, known as Covishield in India, was only 60 per cent effective against the Delta variant. <br />Meanwhile, the Lancet discovered that vaccines are less effective against the Delta variant, especially when given in a single dose. The efficacy of Pfizer-vaccine BioNTech's drops from 92 per cent against the Alpha variant to 79 per cent against the Delta variant after two doses, according to the study.
