Covaxin neutralises both Alpha, Delta variants of Covid effectively, research by top US health institute finds

Bharat Biotech's Covaxin, India's only domestically developed Covid vaccine, can make antibodies that can neutralise both Alpha and Delta variants of the virus, research by the US National Institute of Health (NIH) has found.

"Results from two studies of blood serum from people who had received COVAXIN suggest that the vaccine generates antibodies that effectively neutralize the B.1.1.7 (Alpha) and B.1.617 (Delta) variants of SARS-CoV-2, first identified in the United Kingdom and India, respectively," new agency ANI reported quoting an NIH release.

NIH, America's top health research institute, has had scientific collaboration with India on many earlier occasions.

An adjuvant called Alhydroxiquim-II, developed with the help of NIH funding, is behind the high-efficacy of the vaccine, the research findings showed.

Alhydroxiquim-II is the first adjuvant in an authorised vaccine against an infectious disease to activate receptors TLR7 and TLR8 that play a vital role in the immune response to viruses, PTI reported.

Adjuvants are substances made as part of a vaccine to increase immune responses in people. These are known to raise a vaccine's effectiveness.

The adjuvant is question was discovered and lab-tested by ViroVax LLC of US with help exclusively from the NIAID Adjuvant Development Program, a statement said.

The NIAID Adjuvant Program has supported the research of the founder and CEO of ViroVax, Sunil David, PTI said quoting NIH. David's work has focused on "searching for novel molecules that activate innate immune receptors and developing them as vaccine adjuvants."

Alhydroxiquim-II has a small molecule attached in a special way to Alhydrogel. It may be noted that Alhydrogel is an alum — the most commonly used adjuvant in vaccines for human use. Among other things, the alum in Alhydroxiquim-II prods the immune system to look for incoming pathogens. The stimulation is powerful but the side effects are mild, the NIH said.

Dr Anthony Fauci, the face of America's fight against the virus, said he was pleased that an adjuvant developed in the US has a major role in an efficacious vaccine available to the Indian people.

Covaxin is made of disabled SARS-CoV-2 virus which can't ail the recipient but still works the immune system to make antibodies.

Interim results from Covaxin's Phase 3 trial have reportedly shown over "78% efficacy against symptomatic disease, 100% efficacy against severe infection and 70% efficacy against asymptomatic infection."

Phase 3 safety data of the vaccine will be available sometime later this year. Results from Phase 2 tests have shown that it is safe and well-tolerated.

Covaxin was developed by Bharat Biotech in collaboration with the Indian Council of Medical Research (ICMR).

The vaccine has so far been given to around 25 million recipients in India and elsewhere.

With agency inputs