Delta Plus: What We Know (And Don't) About The New Coronavirus Variant
At least three Indian states have reported cases of a mutated form of the infectious 'Delta' variant of the coronavirus—the most dominant strain globally as of now. However, little is known as to whether the emergence of the new 'Delta Plus' mutation—designated as B.1.617.2.1 or AY.1—is a cause for concern.
About 22 Delta Plus-infected cases have been seen across Maharashtra, Kerala and Madhya Pradesh so far, India's Health Ministry said in a press briefing on Tuesday. The variant has been found in samples from Ratnagiri and Jalgaon districts of Maharashtra, Palakkad and Pathanamthitta districts of Kerala, and Bhopal and Shivpuri districts of Madhya Pradesh.
The central government is wary of the risk. In a press note on Tuesday, it classified Delta Plus as a 'Variant of Concern'—which is more infectious and resistant to treatment. That is the same degree of threat as the 'Delta' mutation which is considered to be the reason for India's deadly second wave.
"The issue looks fairly small in terms of number. But we would not want this to assume significant proportions," Health Secretary Rajesh Bhushan said in a press conference on Tuesday. "The Health Ministry has issued an advisory to states on the kind of public health response they should initiate to address this."
The variant's prevalence is not restricted to India. At least 155 sequences across 10 countries of the AY.1 mutation had been detected by June 21, according to GISAID, an open-access repository for genome data of viruses. This includes the U.K., the U.S., Switzerland, Portugal, Nepal, France, Russia and Canada, among others. The earliest sample of this new variant was isolated in Europe by March.
Is That A Worry?
As of now, it is hard to ascertain whether the new variant should cause alarm. But vigilance is warranted.
The SARS-Cov-2 virus, that causes Covid-19, has had multiple mutations since first being detected in Wuhan, China in late 2019. Some of its variants have become notable for being more infectious and severe.
The highly contagious Delta variant was first detected in India following which the country saw a deadlier second wave of Covid-19. The World Health Organization has said that, increasingly, Delta is becoming the dominant variant across the globe.
Delta Plus has one additional mutation over this—K417N—also seen in the Beta variant of the virus that was detected in South Africa, according to the Council of Scientific and Industrial Research's Institute of Genomics & Integrative Biology. It is the confluence of two variants which has triggered worries.
According to Indian virologist Shahid Jameel, this mutation is known to reduce the effectiveness of a cocktail of antibodies that are used in the treatment of Covid-19. "Though no data is so far available for the Delta Plus variant, we should remain aware and cautious. Active surveillance is needed to detect and isolate the carriers," he told BloombergQuint over email.
Jameel said till the scientific community has better understanding of the variant, citizens should not be too anxious about it.
Since there is, so far, no evidence for the Delta Plus variant in community circulation anywhere in the world, there is no need to panic.Shahid Jameel, Virologist & Director at Trivedi School of Biosciences, Ashoka University
What About Vaccines And Treatment?
With its very limited prevalence, it is unknown whether the current vaccines are effective against the virus or not.
The Delta and Beta variants are less sensitive than the Alpha variant to the antibodies that are generate by vaccines, research from the U.K. government has shown. Despite, the slightly lower level of antibodies, two doses of the vaccines had offered enough protection against any variant to prevent hospitalisation and severe disease in most cases.
The worry about Delta Plus comes from the K417N mutation. "This mutation may contribute to reduced efficacy of several frontline vaccines against the Beta variant of concern," Jameel said.
But clarity can only emerge once further tests on the variant are done. "These results would provide clues to how currently available vaccines fare against the Delta Plus variant. It will take time for the real world effectiveness of vaccines against this variant to be established," he said.
The Indian government is not looking to change the vaccination or treatment protocols for Covid-19 due to the new variant. "You have to understand that the public health response against any variant is standardised," Bhushan said in the press conference.
The U.K. Public Health Department said that studies on the K417N mutation are ongoing.
In India too, a consortium of 28 laboratories—INSACOG—has been established to conduct genome sequencing studies of Covid-19 virus. It is expected to release its findings on the Delta Plus variant soon, according to news agency ANI.
The National Institute of Virology in Pune is also isolating samples of Delta Plus variant, the Times of India reported, to test whether Bharat Biotech's Covaxin is effective against it or not.
Meanwhile, the state of Maharashtra has tied up with the CSIR-IGIB for whole genome sequencing. The institute will sequence 100 Covid-19 positive samples every month from each district in the state.
Till more clues emerge, the government has urged states to step up their measures to curb the spread of Covid. The Health Ministry has advised Maharashtra, Kerala and Madhya Pradesh to take up immediate containment measures in the districts where cases of the new variant have been reported, improve vaccine coverage and increase testing.
States have also been advised to ensure that adequate positive Covid-19 samples are promptly sent to laboratories for studies.
According to scientists at the CSIR-IGIB, because Delta is a variant of concern, any mutations that emerge from it need to be tracked closely.