Inactivated COVID-19 vaccine BBV152/COVAXIN effectively neutralizes recently emerged B.1.1.7 variant of SARS-CoV-2

Abstract

The rapid surge of SARS-CoV-2 cases due to the ‘variant of concern (VOC) 202 012/01’, also known as lineage B.1.1.7 or 20B/501Y.V1 in the UK,1 in December 2020, raised concerns in several countries due to its high transmissibility. Many of these countries had direct flights to and from the UK. Since the identification of the new variants of Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in the UK and South Africa,2 health experts have also expressed their concerns about their potential implications pertaining to vaccine efficacy. The root of such concerns was grounded in the structure of the SARS-CoV-2 variant, VOC-202012/01, which came to the centre stage of discussion due to its greater transmissibility in humans compared with the other known SARS-CoV-2 lineages. This variant carries 17 mutations in the genome, 8 of which have been 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.2 One of these mutations, N501Y, at position 501, has asparagine (N) replaced with tyrosine (Y) and has been identified to increase the binding affinity of SARS-CoV-2 to human and murine ACE2.2 Therefore, it appeared that the majority of the vaccine candidates, being either recombinant or specifically targeting the single epitope of the original D614G ancestral spike sequence, might not be able to generate an efficient immune response against the new variants.