Genome sequencing of SARS-CoV-2 omicron variants in Delhi reveals alterations in immunogenic regions in spike glycoprotein
Loading...
Date
2023-10
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
The SARS-CoV-2 omicron variants keep accumulating a large number of
mutations in the spike (S) protein, which contributes to greater transmissibility
and a rapid rise to dominance within populations. The identification of mutations
and their affinity to the cellular angiotensin-converting enzyme-2 (ACE-2)
receptor and immune evasion in the Delhi NCR region was under acknowledged. The study identifies some mutations (Y505 reversion, G339H,
and R346T/N) in genomes from Delhi, India, and their probable implications for
altering the immune response and binding affinity for ACE-2. The spike
mutations have influenced the neutralizing activity of antibodies against the
omicron variant, which shows partial immune escape. However, researchers are
currently exploring various mitigation strategies to tackle the potential decline in
efficacy or effectiveness against existing and future variants of SARS-CoV-2.
These strategies include modifying vaccines to target specific variants, such as
the omicron variant, developing multivalent vaccine formulations, and exploring
alternative delivery methods. To address this, it is also necessary to understand
the impact of these mutations from a different perspective, especially in terms of
alterations in antigenic determinants. In this study, we have done whole genome
sequencing (WGS) of SARS-CoV-2 in COVID-19 samples from Delhi, NCR, and
analyzed the spike’s mutation with an emphasis on antigenic alterations. The impact of mutation in terms of epitope formation, loss/gain of efficiency, and
interaction of epitopes with antibodies has been studied. Some of the mutations
or variant genomes seem to be the progenitors of the upcoming variants in India.
Our analyses suggested that weakening interactions with antibodies may lead to
immune resistance in the circulating genomes.