Washington: The US-based National Institute of Health (NIH) has acknowledged the effectiveness of Covaxin, the vaccine developed by Bharat Biotech in collaboration with the Indian Council of Medical Research, in neutralising both Alpha and Delta variants of coronavirus.
"Results of two studies of blood serum from people who received Covaxin suggest that the vaccine generates antibodies which effectively neutralise the Alpha and Delta variants of SARS-CoV-2," it said.
"Unpublished interim results from phase 3 trials indicate that Covaxin is 78% efficient against symptomatic disease while its efficacy against severe Covid-19 is 100%. Further, it has shown 70% efficacy against asymptomatic infection with Sars-CoV-2, the Covid-19 causing virus," NIH noted, stressing that the vaccine is "safe and well-tolerated." The vaccine makers recently submitted phase 3 trial data to an expert panel that found it to be 77.8% effective against symptomatic Covid-19, in line with the interim trial analysis.
NIH further said an adjuvant developed with funding from it has contributed to Covaxin's success, describing the shot as "highly efficacious." An adjuvant is a substance formulated as part of a vaccine to boost immune responses and enhance its effectiveness.
Alpha or the B.1.1.7 variant was first detected in the UK, while Delta or the B1.617 variant was first found in India.
Covaxin, along with the Oxford University-Astrazeneca shot, has been used since the beginning of India's nationwide vaccine drive against the viral disease on January 16.
Russia's Sputnik V was given emergency use authorisation (EUA) in April, while US pharmaceutical firm Moderna's mRNA-based vaccine on Tuesday received approval to be used here.
In the coming days, Pfizer and Ahmedabad-based Zydus Cadila could also be approved. If approved, the Zydus Cadila shot will be India's second indigenous anti-Covid vaccine after Covaxin.