The US National Institute of Health (NIH) said that vaccine Covaxin, developed by Bharat Biotech, is highly effective in neutralising both Alpha and Delta variants of coronavirus. "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," the NIH said.
Covaxin comprises a disabled form of SARS-CoV-2 that cannot replicate but still stimulates the immune system to make antibodies against the virus. Published results from a phase 2 trial of the vaccine indicate that it is safe and well tolerated, the NIH said, adding that safety data from a phase 3 trial of Covaxin will become available later this year.
Earlier, the Centre had stated that Covishield and Covaxin work against SARS-CoV-2 variants Alpha, Beta, Gamma and Delta, while effectiveness tests against the Delta Plus variant is ongoing. There are four variants of concern of the coronavirus disease, Alpha, Beta, Gamma and Delta, with Delta Plus being a sub-lineage of the Delta variant which is also a variant of concern.
Addressing a press conference, ICMR Director General Balram Bhargava said reduction of neutralisation capabilities of vaccine with different variants, which is based on global literature, shows that Covaxin does not change with the Alpha variant at all and so it is same as it is with the standard strain. "Covishield reduces slightly with Alpha, by 2.5 times. For the Delta variant, Covaxin is effective, but antibody response is slightly reduced to three-fold reduction, and for Covishield, it is two-fold reduction, while in Pfizer and Moderna it is seven-fold reduction," he said.
"However, Covishield and Covaxin work against the variants of SARS-CoV-2- Alpha, Beta, Gamma and Delta. That is well established for these two vaccines," Bhargava said.
Delta variant spreading across globe
The Delta variant of COVID-19, identified in at least 85 countries, is the most transmissible of the variants identified so far and is spreading rapidly among unvaccinated populations, WHO chief Tedros Adhanom Ghebreyesus had warned earlier. "I know that globally there is currently a lot of concern about the Delta variant, and the WHO is concerned about it too," Ghebreyesus said at a WHO press briefing. The Delta variant was first identified in India.
Delta is the most transmissible of the variants identified so far, has been identified in at least 85 countries, and is spreading rapidly among unvaccinated populations, he said in Geneva. He noted with concern that as some countries ease public health and social measures, we are starting to see increases in transmission around the world. More cases means more hospitalisations, further stretching health workers and health systems, which increases the risk of death, he said.
While pointing out that new COVID-19 variants are expected and will continue to be reported, that's what viruses do, they evolve, but we can prevent the emergence of variants by preventing transmission.
In a strong warning, Dr Maria Van Kerkhove, COVID-19 Technical Lead at the WHO said the Delta variant is a "dangerous" virus and is more transmissible than the Alpha variant, which was itself extremely transmissible across Europe and any country that it entered.
-Inputs from PTI
