In this illustrative photograph, vials labelled ‘Covaxin’ stand on a table. Photo: Reuters
Washington: India’s Covaxin, developed by Bharat Biotech in collaboration with the Indian Council of Medical Research, effectively neutralises both alpha and delta variants of the novel coronavirus, the US’s National Institute of Health has reported in a study.
The NIH said results of two studies of blood serum from people who had received Covaxin suggest that the vaccine generates antibodies that effectively neutralised the B.1.1.7 (alpha) and B.1.617 (delta) variants of SARS-CoV-2, first identified in the UK and India, respectively.
The top American health research institute, which has a history of scientific collaborations with India, also said that an adjuvant developed with its funding has contributed to Covaxin’s success.
This vaccine has been administered to roughly 25 million people till date in India and in some other countries.
Adjuvants are substances formulated as part of a vaccine to boost immune responses and enhance a vaccine’s effects.
Covaxin comprises disabled particles of SARS-CoV-2 – which can’t replicate but still stimulate the immune system to make antibodies against the virus. Results from a phase 2 trial of the vaccine indicate that it is safe and well-tolerated, the NIH said.
The safety data from a phase 3 trial of Covaxin is expected to become available later this year.
“I am pleased that a novel vaccine adjuvant developed in the US with NIAID support is part of an efficacious COVID-19 vaccine available to people in India,” Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases (NIAID), a part of NIH, said.
The adjuvant used in Covaxin, alhydroxiquim-II, was discovered and tested in a laboratory by the biotech company ViroVax LLC of Lawrence, Kansas, with support from the NIAID Adjuvant Development Program.
Alhydroxiquim-II is the first adjuvant in an authorised vaccine against an infectious disease to activate receptors TLR7 and TLR8, which play vital roles in the human immune response to viruses.
The alum in alhydroxiquim-II also stimulates the immune system to search for an invading pathogen. Molecules that activate the TLR receptors stimulate the immune system powerfully, but the side effects of alhydroxiquim-II are mild, the NIH said.
The collaboration between Dr Sunil David, CEO of ViroVax, and Bharat Biotech International Ltd. of Hyderabad was initiated during a 2019 meeting in India coordinated by the NIAID Office of Global Research under the auspices of NIAID’s Indo-US Vaccine Action Program.
Bharat Biotech subsequently signed a licensing agreement with Dr David to use alhydroxiquim-II in their candidate vaccines. This license was expanded during the COVID-19 pandemic to include Covaxin, which has received ’emergency use’ approval in India.