Dubbed the India variant, B.1.617 was first found in March, and has 15 mutations compared to the original virus.
It comes as seven cases of the India variant of Covid-19 were identified in Northern Ireland.The cases, confirmed on Thursday, are the first of the variant to be identified in the province.
Dr Sujeet Singh, director of the National Centre for Disease Control, said the surge in cases seen over the last one and a half month in some states shows a “correlation with the rise in (presence) B.1.617," but stressed the surge is not “fully established”.
“Initially, the epicentre for B1.617 lineage was found to be Maharashtra. The current surge in cases seen over the last one and half month in some states shows a correlation with rise in the B1.617 lineage,” said Dr Singh said.
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“However, its epidemiological and clinical correlation is not fully established… without the correlation, we cannot establish direct linkage to any surge. However, we have advised states to strengthen public health response — increase testing, quick isolation, prevent crowds, vaccination — in those regions where presence of B.1.617 has been noted,” Dr Singh said.
The Indian Express reported the UK had asked India to send samples of the double-mutant to London in order to conduct wider studies on the effectiveness of the existing vaccines against it.
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B.1.617 has been spreading quickly in India and is now the dominant strain in India's second most populous state, Maharashtra in south-western India. Infections in India hit another daily record on Thursday as the number of new confirmed cases was more than 400,000 for the second time since the devastating surge began last month.
The 412,262 cases pushed India’s tally to more than 21 million. A further 3,980 deaths were reported the last 24 hours, bringing the total to 230,168. Experts believe both figures are an underestimate.
Demand for oxygen rose seven-fold with supplies in hard-hit places like New Delhi running critically short.
What is a double mutation?
A double mutation is when two notable mutations found in other variants appear together, although many scientists discourage the use of the word as they believe it is misleading.
“B.1.617 has 13 mutations that result in amino acid changes. B.1.617 has been described as a ‘double mutant’. This term is used to refer to two mutations in spike (E484Q and L452R) but is inaccurate, has no specific meaning and should be avoided," Prof Sharon Peacock, Director of COG-UK, and Professor of Public Health and Microbiology, University of Cambridge said.
In terms of the 'India' variant, Prof Peacock added: "More evidence is needed to understand the virus changes that result from the specific combination of mutations present in B.1.617."