According to experts, the vaccine developed by AstraZeneca and Oxford University showed only 62.1 per cent efficacy, much lower than other major vaccines already approved
Approval of AstraZeneca’s vaccine by the Drugs Controller General of India has stirred some controversy in the public and the scientific community. According to experts, the vaccine developed by AstraZeneca and Oxford University showed only 62.1 per cent efficacy, much lower than other major vaccines already approved for use in mass vaccinations in other countries and there remains uncertainty about its dosage and recommended interval between doses.
Says Dr Debkishore Gupta, Consultant & Head- Clinical Microbiology & Infectious Diseases, Head- Infection Prevention & Control, Ruby General Hospital, Faculty, DNB Microbiology, Assessor-NABL, NABH, WHO Patient Safety, “India approved a full two-dose regimen with no dosing schedule specified. However, when the UK approved the same vaccine last week it was recommended that people get one dose followed by a second four to 12 weeks later in a bid to speed up the vaccination programme with officials claiming efficacy could be as high as 80 per cent with three months between doses. More uncertainty relates to the fact that the vaccine’s clinical trial results published in The Lancet in December demonstrated that a group of volunteers who by mistake received half a dose followed by a full dose showed 90 per cent effectiveness, much higher than the 62.1 per cent for two full doses.”
Dr Gajendra Singh, Public Health Expert says, “It is interesting to note that what may have pushed AstraZeneca virologists to start work on combining their vaccine’s vector with that from Russia’s Sputnik V to see if that could help boost its vaccine’s efficacy. Unlike AstraZeneca, which uses one and the same component for both shots, the Russian vaccine uses two different ones for two separate inoculations and has much higher efficacy shown in Phase III clinical trials – 91.4 per cent.”
