JOIN USIndia’s COVID-19 landscape a melting pot of mutations
India is a veritable hodgepodge of COVID-19 viral mutations, brought back by international travellers before the country sealed its borders in late March.
The presence of such a range of mutations of the Sars-Cov-2 virus in India’s population could have serious implications in the accuracy of diagnostic tests and even creating a vaccine, preliminary research at the Indian Institute of Science (IISc) suggests.
Already, researchers working worldwide have identified several key mutations to the Sars-CoV-2 virus, which could potentially make the disease more infectious.
On Tuesday, a paper published by US-based scientists suggested that one particular subtype of the virus, involving a mutation at the 614th position of the Spike protein (D614G) is rapidly becoming dominant and could potentially make the disease more virulent. This D614G mutation possibly generates an additional serine protease cleavage site near its virus’ S1-S2 junction of the Spike protein. This, with the combination of a nucleotide deletion (delC) allele present in some people (depending on your genetic makeup), accelerates the spread of the virus into a person.
This paper is still under peer-view and has not yet been formally published.
Two different strains in India?
The D614G mutation is also present in Indian genomic samples being uploaded to the Global Initiative in Sharing All Influenza Data (GISAID) database, which is the primary source of all Sars-Cov-2 research being conducted worldwide.
Researchers at the Department of Microbiology and Cell Biology, Indian Institute of Science (IISc), who have been analysing these genomic sequences have also found that the virus in India falls into two distinct strains. Many of them show similarities to specific countries hit by the pandemic.
The findings, published in a paper which is still under peer-review, postulates that these “may have important consequences with respect to virus transmission rate and virulence, the extent of the disease severity and various other aspects of disease pathogenesis”.
Over fifty percent of Indian sequences fall into viral clade (or strain) G, which is the virus strain prevalent in Europe, plus some Middle East and South Asian nations. This shows that this strain was brought back to India primarily by travellers from Europe, who were also passing through places such as Dubai and Abu Dhabi. Most of the remaining Indian samples fall into clade I, a strain of the virus now identified as being in Iran, Saudi Arabia and Kuwait, with a connection to Oceania.
But would not the presence of G clade viruses in India mean that the country should also expect to suffer the same high rate that Europe has been experiencing?
"Yes. It should. But the fact that it has not is simply mind-boggling. We just don’t know why yet,” said a senior microbiologist at IISc who did not want to be named.
Implications for testing, vaccination
The presence of such multiple strains of the Sars-Cov-2 virus in India’s population could have serious implications in the accuracy of diagnostic tests and even creating a vaccine, the IISc paper states.
Special diagnostic kits based on the type(s) of clades prevalent in an area would possibly need to be developed, the paper adds.