As much as 61% of the Covid-19 samples taken from Maharashtra between January and March for genome sequencing have shown a double mutation of the virus, The Indian Express reported on Wednesday. This is being suspected as one of the factors behind the massive second wave of coronavirus in India.

As many as 220 of the 361 samples taken for genome sequencing showed the mutation, officials of the National Institute of Virology in Pune said during a presentation on April 10 to all district heads of government laboratories in Maharashtra.

However, the Centre is yet to flag the double mutation variant of the virus as a matter of concern. It has not said if a different strategy was needed to tackle the variant despite state health officials repeatedly raising the matter, according to The Indian Express.

“The Centre has maintained that there is no need to change the strategy,” State Health Secretary Pradeep Vyas said. In fact, the Maharashtra government has not yet received a written report on the data shared verbally by the National Institute of Virology. State Health Minister Rajesh Tope has asked the Centre for a detailed report on the genome sequencing of all the Maharashtra samples.

Last month, the Centre had said that the double mutant variant and “variants of concern” had been detected in 18 states in India. It said that the mutations were found in 15%-20% of the analysed infected samples from Maharashtra but did not link the variant with the second wave.

The double mutation, as the name suggests, involves two variants of the virus. The E484Q mutation has characteristics of a previously detected variant – the E484K – which was seen in the fast-spreading Brazilian and South African variants, making it highly transmissible. The L452R mutation, on the other hand, helps the virus evade the body’s immune response. The double mutation strain was subsequently named B.1.617.

Also read:

India played down new mutant Covid strains to avoid panic – but this may have backfired

The National Institute of Virology showed that the double mutant variant B.1.617 first appeared in Maharashtra in three samples in Akola and one sample in Thane. By February, the variant was detected in more than 50% samples in 13 districts, including Akola, Amravati, Bhandara, Hingoli, Gondia, Chandrapur, Nagpur, Pune, Wardha and Yavatmal. A month later, in March, the variant was found in Aurangabad, Mumbai, Jalna, Palghar and Nanded as well.

Sujeet Singh, the Director of National Centre for Disease Control, told the newspaper that the variant was of interest but it cannot be directly linked to the surge as the number of samples were too few.

However, Shashank Joshi, a member of Maharashtra’s Covid-19 task force, stressed on the need to do district-wise sequencing to understand local viral behaviour. “This is something we flagged two months ago,” Joshi said. “This variant is fast spreading, has exponential growth and has strained our health system.”

Medical scientist Dr Gagandeep Kang, professor of microbiology at the Christian Medical College in Vellore, also highlighted the need to put together data to understand how the mutation will affect people. “We know that the South African variant is more capable of escaping immune response...We know that the UK variant is the most transmissible,” Kang said. “But we know nothing about the B.1.617 variant because we are not putting together data to draw conclusions.”