Covaxin is one of two coronavirus vaccines currently in use in India (File)
Covaxin, the coronavirus vaccine developed and manufactured by Bharat Biotech, "neutralises multiple variants of SARS-CoV-2 and effectively neutralises the double mutant strain as well", the ICMR, the Indian government's top medical research body, said on Wednesday.
The ICMR (Indian Council for Medical Research) did not, however, provide data to back this claim.
Twenty-four hours earlier, though, Bharat Biotech's Dr Krishna Ella told NDTV there is "no information yet" about how well the vaccine might work against variants of the coronavirus. He said the data - specifically efficacy against the double mutant strain - was not expected for a week.
"I don't know about the South African variant yet... but coming to the Indian double mutant, we don't have knowledge, we will have data in about a week," Dr Ella, the chairperson of the Hyderabad-based vaccine firm, told NDTV in an exclusive interview.
Dr Ella also indicated the timeline - "a week" - was only an estimate, and said: "I don't want people to bug me saying you said one week... it takes time for us... We are very serious about it."
"We don't want a vaccine which doesn't work," he stressed.
The government body's claim was after Bharat Biotech released second interim results from an analysis of 87 participants in its Phase III trial data who tested positive for the virus.
The study showed Covaxin had a "vaccine efficacy of 78 per cent against mild, moderate, and severe COVID-19 disease", and that "efficacy against severe COVID-19 disease was 100 per cent".
In early March the company released first interim results, which pegged efficacy at 81 per cent.
Dr Ella's comments appear to underline the contradiction between the two sides' take on Covaxin's efficacy against mutated, and potentially more aggressive, versions of the virus.
In March India's junior Health Minister, Ashwini Choubey, told parliament the vaccine had "good efficacy against variants". A week later ICMR chief Dr Balram Bhargava said Covaxin and Covishield (the vaccine produced by the Serum Institute) "are effective against UK and Brazilian variants".
The double mutant strain - labelled B.1.617 - is a possibly more infectious variety that was first detected in Maharashtra late last year, and which experts have linked to the spike in Covid cases.
The average prevalence of the variant surged to 52 per cent of samples sequenced in India so far this month - from almost nothing in January - a Bloomberg report, referring to outbreak.info, said.
The Indian government only acknowledged its presence last month, and last week Health Ministry sources told NDTV it could be responsible for the rising infections. Since then, the strain has also been confirmed in 10 countries, including the United States, Australia and parts of Europe.
Debate over Covaxin's efficacy against various strains (this morning a triple mutation was reported) comes as India prepares to throw open vaccination to all adults (i.e., over 18) from May 1.
Earlier on Wednesday Bharat Biotech released second interim results of more than 87 symptomatic participants in its Phase III trials; the data showed it was 78 per cent effective "against mild, moderate and severe" cases, and "the efficacy against severe COVID-19 disease was 100 per cent".
With input from PTI