Coronavirus: Delta variant

'Delta Plus' is a variant of concern, says New Delhi

Scientists say it is highly transmissible and potentially resistant to treatment by monoclonal antibodies

Residents in Kolkata taking photos of a paper lantern with Covid-19 guidelines and reminders on it on Tuesday. India yesterday reported 50,848 new Covid-19 cases in the past 24 hours, taking its total number of cases to more than 30 million. People s
Residents in Kolkata taking photos of a paper lantern with Covid-19 guidelines and reminders on it on Tuesday. India yesterday reported 50,848 new Covid-19 cases in the past 24 hours, taking its total number of cases to more than 30 million. PHOTO: AGENCE FRANCE-PRESSE
Residents in Kolkata taking photos of a paper lantern with Covid-19 guidelines and reminders on it on Tuesday. India yesterday reported 50,848 new Covid-19 cases in the past 24 hours, taking its total number of cases to more than 30 million. People s
People shopping at a wholesale vegetable market in Delhi yesterday, after the authorities in India eased Covid-19 restrictions as the country emerges from a calamitous second wave of infections. However, there are concerns that a third wave could be dominated by new and potentially more contagious variants of the coronavirus. PHOTO: REUTERS

A new variant of the Delta strain of the coronavirus - named "Delta Plus" because of an additional mutation - has been labelled a variant of concern (VOC) by the Indian government.

This was announced on Tuesday after scientists from a consortium of genomic sequencing laboratories told the government they had found evidence suggesting that the new variant is highly transmissible, with strong binding to lung cells and potential resistance to treatment by monoclonal antibodies.

The news came as India yesterday reported 50,848 new Covid-19 cases in the past 24 hours, taking its total number of cases to more than 30 million.

As the country emerges from a calamitous second wave of infections, there are concerns that a third wave could be dominated by new and potentially more contagious variants.

An analysis of more than 45,000 samples has so far revealed about 40 cases of the Delta Plus variant in at least six districts in the states of Maharashtra, Kerala and Madhya Pradesh.

The Ministry of Health and Family Welfare has advised these states to take "immediate containment measures" in the affected districts. Measures suggested include preventing crowds from gathering, widespread testing, prompt tracing and widespread vaccination.

The ministry has also directed the three states to promptly send samples of patients to government labs for further epidemiological studies.

There are two reported Delta Plus lineages, known formally as Delta-AY1 and Delta-AY2. These lineages have been found in several other countries, including Britain, the United States, Canada, Japan, Nepal, Poland, Portugal, Russia, Switzerland and Turkey.

According to the Gisaid data-sharing platform on Covid-19, a majority of these reported cases as at June 16 were from the US, Britain and Portugal. The lineage reported in India so far is Delta-AY1, which is currently more prevalent globally.

A government statement yesterday said a "retrospective analysis of samples" showed the presence of the AY1 lineage in a sample collected from Maharashtra on April 5. Some media reports have suggested that the variant was identified as early as March in Europe.

Dr Anurag Agrawal, director of the CSIR Institute of Genomics and Integrative Biology (IGIB), said the Delta-AY1 variant has been labelled a VOC because all Delta variants, by default, are VOCs.

He told The Straits Times: "One must distinguish a situation of concern from a public health point of view and a variant of concern from a molecular point of view."

The IGIB is part of a consortium of 28 labs that has been sequencing coronavirus samples in India and advising the government.

The highly contagious Delta variant was largely responsible for the devastating second wave in India and has been linked to a resurgence in cases in several countries.

The Delta Plus or Delta-AY1 variant also demonstrates high transmissibility and strong cell-binding properties.

Dr Agrawal said the new variant's additional properties are still under investigation.

While its prevalence among samples sequenced in India is stable, he said every Delta sublineage merits full and detailed investigation. "One must keep track of this across the world, not just in India."

While the number of reported Delta Plus infections is still small - about 166 on Gisaid - scientists have said it is vital to ensure adequate and prompt genome surveillance to monitor any increase in its frequency in infections globally.

There is so far no evidence to suggest the variant is more fatal. Neither is there any publicly available data on how effective vaccines used in India are against the strain.

Dr Om Shrivastav, a member of Maharashtra's Covid-19 task force, said one must take into account the possibility that newer mutations such as Delta Plus could lead to different Covid-19 symptoms.

He said symptoms caused by the Delta strain now are not shortness of breath or other complications associated with lungs, but gastrointestinal disturbances such as nausea and vomiting.

"There is no such thing as classic symptoms of Covid-19, and you ought to be very alert to anything that is not responding to standard paracetamol or a treatment that may have worked in the past."

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A version of this article appeared in the print edition of The Straits Times on June 24, 2021, with the headline 'Delta Plus' is a variant of concern, says New Delhi. Subscribe