Covaxin effectively neutralises Alpha, Delta variants, says US research institute The NIH said results of two studies of blood serum from people who had received Covaxin suggest that the vaccine generates antibodies that effectively neutralise the B.1.1.7 (Alpha) and B.1.617 (Delta) variants of SARS-CoV-2, first identified in the UK and India Covaxin efficacy against Alpha, Delta COVID-19 variants PTI Updated Jun 30, 2021, 8:03 AM IST India's Covaxin, developed by Bharat Biotech in collaboration with the Indian Council of Medical Research, effectively neutralises both Alpha and Delta variants of coronavirus, the US' National Institute of Health has said. The NIH said results of two studies of blood serum from people who had received Covaxin suggest that the vaccine generates antibodies that effectively neutralise the B.1.1.7 (Alpha) and B.1.617 (Delta) variants of SARS-CoV-2, first identified in the UK and India, respectively.