April 28 2021 at 03:33 AM by Samikshya Joshi
NEW INDIAN DOUBLE-MUTANT COVID-19 STRAIN UPDATE-13
Indian genome scientists have detected a so-called "double variant" of the novel coronavirus. When covid infections began dropping in India in September, many concluded the worst had passed. Social distancing and masks were abandoned, while the government gave mixed signals about the level of risk. When cases began rising again in February, authorities were left in a dilemma.
Nobody took a long-term view of the pandemic. Everybody thought that it would be controlled as was previously done. But they were wrong. The new mutant spread even faster and was more infectious than the other variants.
In late March, India’s National Centre for Disease Control, announced that a new variant – dubbed a “double mutant” – had been identified in samples of saliva taken from people in Maharashtra, Delhi, and Punjab. This comes on the back of a month that has seen a surge in cases of COVID-19 across India, with many states re-imposing curfews, restrictions, and lockdown measures.
What is the double mutant?
Like all viruses, the coronavirus keeps changing in small ways as it passed from one person to another. But in some mutations changes in the spike protein that the virus uses to latch on to and enter human cells - these variants could potentially be more infectious, cause more severe disease or evade vaccines. Indian genome scientists have detected a so-called "double variant" of the novel coronavirus. The double mutant strain is a combination of two variants – E484Q and L452R — both of which have been present in India for the past few months separately. This new strain was identified through genome sequencing by the Indian SARS-CoV-2 Consortium on Genomics (INSACOG), a group of 10 national laboratories established by the health ministry in December to study genetic mutations.
A virologist at Louisiana State University Health Sciences Center Shreveport, says the E484Q is similar to E484K - a mutation seen in the B.1.351 (South Africa) and P.1 (Brazil) variants, which have emerged independently several times.
If enough mutations happen in a viral family tree or a lineage, the virus can begin to function differently and the lineage can become a so-called 'variant of concern'.
As far as the L452R mutation - also found in the "double mutation" in India - it first got attention as part of B.1.427/B.1.429 lineage in the US, which is sometimes called the "California variant". Mutations in the spike gene can make the virus inherently "better" at infecting people or can help the virus to escape neutralizing antibodies. This means that it can reinfect someone who has already recovered from Covid-19. But if the virus can use reinfection to spread, then it would be "penetrating" herd immunity. This puts the most vulnerable people at risk of severe disease, since the virus can move through the herd to reach them.
The emergence of these new variants has only been possible because of the continued viral replication in areas with high circulation. In the double mutant both the mutations are concerning because they are located in a key portion of the virus – the spike protein – that it uses to penetrate human cells. Spike proteins attach via a “receptor binding domain”, meaning the virus can attach to receptors in our cells.