The company said the phase-4 trials are also being done to “ensure its vaccine met every rigorous scientific standard for safety, effectiveness, and manufacturing quality needed to support emergency use authorization (EUA)”. Covaxin had received EUA in early January while Phase-3 trials were underway, resulting in a controversy.
“It is important to note, the inoculation, which began in mid-January and with several million doses administered, will have credible and sizeable data soon. It is critical to understand and further emphasise the Phase-3 data will first be submitted to Central Drugs Standard Control Organisation (CDSCO), followed by peer reviewed journals…and Phase-3 results full trial data will be made public during July,” it said.
“Covaxin is the only vaccine to have conducted and completed one of the largest ever Phase-3 efficacy trials in India, most other Covid-19 vaccines have only conducted immunogenicity studies and not efficacy studies in the Indian population,” it added.
Bharat Biotech’s statements come in the wake of a Twitter spat between Bharat Biotech’s business development and advocacy head Raches Ella and Kolkata-based endocrinologist Dr Awadhesh Kumar Singh over the latter’s study comparing immune responses of Covaxin and Covishield. The exchange saw Singh and other Twitterati demand that Covaxin Phase-3 trials data be made public.
Explaining the reasons for the time being taken to make the data public, he said the Covaxin Phase-3 trial was the largest efficacy trial conducted in the developing world with a sample size of 25,800, with the last volunteer being vaccinated in mid-March.
Bharat Biotech also slammed the Singh-led comparative study as flawed. “This is not a peer reviewed publication, nor statistically and scientifically designed study, the study design and conduct reflect an ad hoc analysis, rather than a predetermined hypothesis,” it said. Covaxin showed an overall interim efficacy of 78% and 100% efficacy against hospitalisations.