A study conducted by a group of researchers from the Indian Institute of Science (IISc) has found that the SARS-CoV-2 virus, which causes COVID-19, is mutating faster in Bengaluru, compared to the national and global average mutation rate. The study which was recently published in the Journal of Proteome Research found that virus samples from Bengaluru had 27 mutations in their genomes, with over 11 mutations per sample, which is higher than both the national average of 8.4 and global average of 7.3.
The study, carried out by a team of researchers from IISc’s Department of Biochemistry, analysed virus samples recovered from nasal secretions of individuals who tested positive for the novel coronavirus in Bengaluru, to achieve a better understanding of the protein biology of the SARS-CoV-2 virus and how it is mutating.
Apart from finding a faster mutation rate in the virus in samples from Bengaluru, the team also provided first evidence of expression of a protein (called Orf9b), which suppresses the immune response in an infected person and was predicted to be present in the virus. In total, the team detected 13 different proteins from the virus samples, most of which were previously unidentified, according to an IISc statement on the findings of the study.
The study involved a process called next generation sequencing (NGS), a technology that allows rapid sequencing of the entire genome. In the IISc statement, Professor Utpal Tatu, who led the research team, was quoted as saying that sequencing the genomes of viral strains from around the world is important to keep track of mutations that are constantly arising. While the SARS-CoV-2 genome codes for more than 25 proteins, a handful of these proteins have been identified so far, the statement said.
The study also examined host proteins to understand how infected persons respond to the virus, and the team discovered around 441 proteins unique to COVID-19 patients. Many of these proteins are speculated to play an important role in the body’s immune response to the virus.
The study also found that samples of the virus in India have not evolved from a single ancestral variant but have multiple origins.
Although several mutants and variants of the SARS-CoV-2 virus have been detected, scientists have noted that mutations aren’t necessarily a cause for concern. While every virus is known to mutate, it’s the rate of mutation which must be taken into consideration, Dr Shahid Jameel, a virologist and the Director of the Trivedi School of Biosciences at Ashoka University, had previously told TNM. He noted that coronaviruses are the slowest mutating RNA virus known to humans, roughly 1,000 times slower than the flu virus. Scientists have also noted that the mutations observed so far are not likely to impact the efficacy of the vaccine.