By Team Ayurved Sutra
Posted on
Genetic recombination made Omicron more infectious
New Delhi (India Science Wire): Viruses like SARS-CoV-2 keep changing their
genetic makeup to escape human immune response. One of the ways they can change
rapidly is Genetic Recombination which happens in a person co-infected with two
different SARS-CoV-2 strains simultaneously. Researchers from the Department of
Microbiology & Cell Biology, and the Centre for Infectious Diseases Research, Indian
Institute of Science Bangalore, have found that recombination events had escalated during
the Omicron wave, which made the virus more immune-evasive and infectious.
Genetic recombination is an essential driver of SARS-CoV-2 evolution, which requires the
coinfection of a single host cell with different SARS-CoV-2 strains. The team comprising
Rishad Shiraz and Shashank Tripathi found that in the event of recombination, two-parent
strains can give rise to a hybrid Recombinant virus, which has features of both parent
strains. Researchers examined the role of recombination in the evolution of SARS-CoV-2
since the beginning of the pandemic.
“Understanding the drivers, mechanisms, and trajectories of SARS-CoV-2 evolution is crucial
to plan mitigation measures, especially vaccine design. We have discovered an
unprecedented escalation in the recombination of SARS-CoV-2 during the Omicron wave.
The cause of this could be more co-infections and few molecular changes in viral proteins of
Omicron. The effect of this was increased transmission and immune evasion by the
Omicron strains,” the team informs India Science Wire.
“We curated SARS-CoV-2 full-length genome sequences from all the public databases,
deposited from the start of the pandemic till the peak of the Omicron wave. We analysed
these sequences using specialized programs to identify recombinant lineages, their parent
strains, and their prevalence across time and geographical locations. We also examined the
protein sequence changes accumulated through recombination, especially in the Spike of
Omicron strains, which were reported to increase viral immune evasion and transmission,”
researchers explain.
Enhanced recombination can increase the chances of new strains emerging, therefore,
tracking such recombination through regular virus sequencing is very important.
“In humans and wild animals, continuous genomic surveillance of SARS-Cov-2 globally is
crucial for understanding the SARS-CoV-2 evolutionary trajectories and pandemic
preparedness,” researchers observe.
The study has been published in Journal of Medical Virology. (India Science Wire)
