Delta Plus, a new variant of the novel coronavirus, has just begun to raise its head in India prompting administration in at least 11 states to be on the guard. The variant, also known as AY.1, is characterised by a mutation called K417N in the spike protein of the virus. This mutation which helps the virus to evade immunity has earlier been reported in the Beta variant.
As of now among nearly 50,000 samples sequenced in India, Delta Plus has been seen in 49 cases sporadically in Maharashtra, Kerala, Tamil Nadu and Madhya Pradesh. More than 200 sequences of AY.1 lineage have been detected worldwide, with the USA and UK having over half the known cases. In an interview noted virologist Shahid Jameel, director of the Trivedi School of Biosciences at Ashoka University spoke to DH’s Kalyan Ray on the new variant. Here are some excerpts:
Is there any evidence on the perceived seriousness of the Delta Plus variant of SARS-CoV-2?
No, there is no evidence that Delta Plus causes more or less serious illness compared to Delta or another Variant of Concern (VoC). There are only about 250 sequences in the public database, including seven from India (but we know there are more than 40 sequences from India by now). This is too few a number to know if it is more infectious/transmissible or causes more serious illness.
That is one incident of death out of over 40 known Delta Plus confirmed cases in India. That says nothing.
Is there any link with increased positivity in western Maharashtra districts that has seen one death?
Hard to say at this time, but more transmission will give it a chance for more mutations. It is also possible that it was introduced there and spread in a cluster. I believe more epidemiological analyses are ongoing.
The most talked-about mutation in Delta Plus was there in another VoC. So why the concerns now
It is of concern because a key mutation from the Beta VoC is now added into the Delta VoC. We don't yet know if for vaccine effectiveness, this acquisition is going to stay neutral or become additive or the new variants will behave as more than the sum of its parts.
What should be the public health responses?
At this time we need to know how it is spreading. For that strategic sequencing of representative samples is needed from places it has appeared in, as well as randomly in other states. It is bound to spread at least as well as Delta. The UK is using a genotyping assay for Delta Plus that is cheaper and faster than sequencing. We should also consider that as well.
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