The "new double mutant variant" of the novel coronavirus has been found in India, the National Centre for Disease Control (NCDC) recently reported.
Now, whether this new strain is resulting in a huge spike in coronavirus cases in the country is the big question.
The variant, classified as 'B.1.617', has been found in eight nations, with 70% of samples comprising mutations believed to have stemmed from India.
Experts have termed the "new double mutant strain" a desi (Indian) variant. At first, strains 'E484Q' and 'L425R' were enabling double mutations, causing more infectious variants of COVID-19.
"There is another mutant called the E484K mutant, a slight variation of which is now a part of the Indian variant. The double mutant that India is talking about is a variant that has 15 different mutations. It just happens to be that there are two critical mutations in the region of the spike protein, one of those mutations was found in California, and it led to an increase in virus transmission in southern California so if it happened there why wouldn't it happen in India," Dr. Shahid Jameel, virologist and Director, Trivedi School of Biosciences at Ashoka University told India Today TV.
"If you compare this virus to the virus that came out of Wuhan that is our reference strain. Compared to that, there are 15 different changes that have also functionally changed the virus in some way. Three of those changes are in the spike protein. This is the protein that is responsible for allowing the virus to get inside the human cells. This is also the protein against which antibodies protect against viral infection. When these changes happen, they lead to the evasion of immune responses. These changes also allow the virus to get into human cells a little better and therefore become more infectious," Dr. Jameel added.
Are COVID-19 vaccines tested against desi variant?
Both Covishield and Covaxin have been tested against the UK variant of the novel coronavirus, and it was found that both jabs protect against the UK variant. However, immunity doesn't work basis one antibody binding to some variants of the virus, Dr. Jameel noted.
"Immunity works on the basis of multiple antibodies binding to multiple sides of the virus. Immunity also works based on T-cells which remove virus-infected cells. One of the misnomers people have about infection, none of the vaccines has been tested against infection. All vaccines provide protection from disease," he stated.
"The India strain is a hybrid of the South African, the UK, and the Brazilian strain in some way. We have only found one or two which we call double mutants; there may be hundreds of them. The Covishield (AstraZeneca) vaccine when it was tried in the South African variant was no better than water," said Dr SK Sarin, head of ILBS Hospital and key advisor to the Delhi government.
"We are clear that some variants in India started with a South African variant somewhere in the month of March. We may have a surge of South African variants where one vaccine may not work. Even Sputnik-V may not work against some variants," he added.
What's the role of desi mutant in India's second COVID-19 wave?
Experts say that it is the nature of viruses to mutate, indicating that around 5,000 mutant variants have been detected since India began sequencing coronavirus mutations. Experts caution that the virus doesn't even want people to develop herd immunity.
"Suppose you are infected with one virus in the past, you may get a second or third infection," said Dr SK Sarin.
India's daily count of new coronavirus infections is approaching the 2 lakh mark, with the new variant now prevalent in many states. In Maharashtra, 61% of the total logged COVID-19 cases have the desi mutant variant. Similar cases are also being reported in Uttar Pradesh, Chhattisgarh, Delhi, and Gujarat.
"Every state will see some spreader events. The question also arises - why not in Bihar in 2020? because the virus hadn't mutated to this extent," said Dr. Jameel.
"The UK variant evades immunity a little better, it transmits better. It is prevalent in Punjab and is coming up quite effectively in Delhi as well," he added. Meanwhile, epidemiologists are of the opinion that there have been considerable mutations.
"We haven't understood this bullet completely. We don't know the extent of these homegrown variants of concern as compared to the imported variants," said Dr. Giridhar Babu, Professor and Head Lifecourse Epidemiology, PHFI.