40 cases of Delta Plus variant found in India
Centre writes to Maharashtra, Kerala, Madhya Pradesh to step up surveillance
NEW DELHI: Around 40 cases of the “Delta Plus” variant have been detected sporadically in Maharashtra, Kerala and Madhya Pradesh, the Union health ministry said on Wednesday, a day after it was declared a variant of concern (VOC) in India citing an analysis by a consortium of genomic sequencing labs that has purportedly found the mutated virus to spread more readily, affect the lungs more strongly, and possibly reduce the ability of some antibodies to neutralise it.
The Delta Plus, scientifically known as the AY.1 variant, appears to be a further evolution of the Delta variant (or B.1.617.2, which was first seen in India) with a particular mutation known as K417N, which has separately demonstrated properties that could make it more resistant to vaccines as well as immunity from a past infection.
“As of now among the samples sequenced (45,000+) in India, Delta Plus variant -- AY.1 -- has been observed sporadically in Maharashtra, Kerala and Madhya Pradesh, with around 40 cases identified so far and no significant increase in prevalence,” the ministry said a statement.
These three states have been advised to strengthen surveillance and take appropriate public health measures.
After the report of AY.1 by the Public Health England (PHE) on June 11, retrospective analysis of samples revealed the first occurrence of this lineage from a sample collected from Maharashtra. The sample was collected on April 5. As of June 18, 205 sequences of AY.1 lineage was detected worldwide, with the US and the UK having over half of the known cases, the statement said.
Insacog -- an Indian consortium of 28 labs, established by the Government of India to carry out genome sequencing of the virus causing the Covid-19 pandemic -- had recently identified a viral variant (Delta, B.1.617.2). This viral variant has also been seen in nine other countries of the world. The World Health Organisation (WHO) has introduced a classi
fication as VOC (variant of concern) and VOI (variant of interest), with the evolution of several variants around the globe.
Delta variant as well as all Delta sub-lineages, including Delta Plus, are classified as VOC, the statement said.
At present, there are four VOCs recognised by the World Health Organization (WHO): Alpha, Beta, Gamma and Delta. Each of these has a unique constellation of mutations that separately or collectively make the virus more transmissible, virulent or resistant. The Delta variant is the first that is believed to do all three.
Delta Plus is the addition of a mutation identified as K417N, which has also been found in the Beta variant. Beta, or B.1.351 seen first in South Africa, is regarded as one of the most resistant variants of the coronavirus till now.
The Indian Sars-CoV-2 Genomic Consortia (Insacog) reported the evolution of Delta plus variant (B.1.617.2) + K417N lineage of Sars-CoV-2 called as B.1.617.2.1/AY.1. The Delta plus variant B.1.617.2.1/(AY.1) is characterized by the K417N mutation in spike protein, the statement said.
The spike protein aids the virus to gain receptor-mediated entry into human cells. K417N corresponds to the change of amino acid lysine (K) to asparagine (N) at the 417th position of spike protein. There are other Delta plus variants with other mutations. The AY.1 is the most well-known, but these are not identical. A second clade found in sequences uploaded to GISAID from the US, is now designated AY.2, but is not seen in India yet, the statement said.
“All Delta sub-lineages are treated as a variant of concern VOC, although properties of AY.1 are still being investigated. Currently, the variant frequency of AY.1 is low in India. Cases with AY.1 have been mostly reported from nine countries of Europe, Asia and America,” the ministry statement stated.