HYDERABAD: India's first indigenous Covid-19 vaccine Covaxin effectively neutralises the deadly and infectious UK variants of SARS-CoV-2 virus, reducing the possibility of mutant virus escape, its developer Bharat Biotech said on Wednesday.
The research paper 'Neutralisation of UK-variant VUI-202012/01 with Covaxin vaccinated human serum’, was also uploaded on bioRxiv, a server that carries preprints of research work before it is peer reviewed.
“We performed the plaque reduction neutralization test (PRNT50) using sera collected from the 26 recipients of BBV152/COVAXINTM against hCoV-19/India/20203522 (UK-variant) and hCoV27 19/India/2020Q111 (heterologous strain),” the paper said.
“A comparable neutralization activity of sera of the vaccinated individuals showed against UK-variant and the heterologous strain with similar efficiency, dispel the uncertainty of possible neutralization escape,” the research paper added.
“The genome of the UK-variant has seventeen mutations, eight of which were found in spike receptor-binding domain (RBD) mediating the attachment of the virus to the angiotensin converting enzyme 2 (ACE2) receptor on the surface of human cells,” the researchers said.
“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,” it said.
“Here, we successfully isolated and characterized the hCoV-19/India/20203522 SARS-CoV-2 (VOC) 202012/01 from UK returnees in India with all signature mutations of the UK-variant,” the paper said.
“COVAXIN developed by @BharatBiotech with @ICMRDELHI has equivalent immunogenicity against the UK-variant & circulating strains of SARS-COV-2 in India. @icmr_niv is the first in the world to culture the UK variant,” tweeted the Indian Council of Medical Research, which has co-developed Covaxin.
Covaxin, which is undergoing Phase III efficacy trials on around 26,000 volunteers at 25 sites across the country, has been approved for Emergency Use Authorisation (EUA) by the country’s drug regulator Drug Controller General of India (DCGI) on January 3, 2021. The company recently said that half the volunteers (13,000) participating in the trials have been administered the second dose of Covaxin.