This weekend’s approval of AstraZeneca’s vaccine by the Drugs Controller General of India has stirred some controversy in the public and the scientific community. Apart from the most obvious point – the vaccine, developed by AstraZeneca and Oxford University showed only 62.1 percent efficacy, much lower than other major vaccines already approved for use in mass vaccinations in other countries – there remains uncertainty about its dosage and recommended interval between doses.
“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 percent 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% effectiveness, much higher than the 62.1 percent for two full 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.
“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 percent,” adds Dr. Gajendra Singh, Public Health Expert.
Interestingly, US Food & Drug Administration (FDA) in a statement released only yesterday highlighted the dangers of experiments with doses, vaccine combinations and time between shots. While these are all valid medical questions to ask during clinical trials to determine what works best, after a vaccine is approved for use, making such alterations, unless they are solidly rooted in scientific evidence, could put public health at risk.
This article is an opinion piece specific to the Indian and not the international context.