NEW DELHI: Scientists at the ICMR’s National Institute of Virology (NIV) and Bharat Biotech have found that Covaxin has similar efficacy against both the UK and variant of coronavirus prevalent in India.
Covaxin, developed jointly by Bharat Biotech and the ICMR, had received the restricted emergency use authorisation by India's apex drug regulator along with Oxford University-AstraZeneca’s Covishield, but is still to complete its phase 3 trials to prove its efficacy.
However, both the regulator and the company had stressed that Covaxin can generate antibodies against multiple proteins instead of spikes alone which in theory suggests that it might have a better chance against the mutated variants.
The latest scientific paper, released on Tuesday, which is yet to be peer-reviewed, has confirmed it.
“A comparable neutralization activity of the vaccinated individuals' sera showed against UK-variant and the heterologous strain with similar efficiency, dispel the uncertainty of possible neutralization escape,” says the paper.
The UK variant has 17 mutations, eight of which are found in the spike protein.
“Therefore, it appeared that the majority of the vaccine candidates, being either recombinant or specifically targeting the single epitope of original D614G ancestral spike sequence, might not be able to generate an efficient immune response against the new variants,” the paper adds.
ALSO READ | Phase-I trial results show Covaxin has tolerable safety, enhanced immunity: Lancet study
Covaxin has been developed from the whole inactivated virus and is not based solely on the spike protein.
The experiment was conducted at the NIV, Pune, using the sera of 26 trial participants who had been vaccinated with Covaxin. The serum is a component of blood that includes antibodies, which is used by the body in its fight against pathogens.
The antibodies of the vaccinated trial participants were used against three strains of the Covid-19 virus for the experiment — hCoV19/India/2020770, which was used by the NIV for the development of Covaxin, hCoV-19/India/2020Q111, a local strain that has been circulating in India, and the hCoV-19/India/20203522, the mutant UK strain.
“Our study evidently highlighted comparable neutralization activity of vaccinated individuals’ sera against variants as well as heterologous SARS-CoV-2 strains,” researchers said. “Importantly, sera from the vaccine recipients could neutralise the UK variant strains discounting the uncertainty around potential escape.”
The scientists concluded that it is “unlikely” the UK variant will “dampen the potential benefits of the vaccine in concern”.
Covid-19 vaccines by Pfizer-BioNTech and Moderna, being used in the US and several European countries have also been shown to work against a host of different strains of SARS CoV 2, including B.117 or UK strain that has been found to be more infectious and potentially also more fatal.