As many as 40 cases of Delta Plus variant of Covid-19 have been reported in the country, the Health Ministry said. It said that most of the cases are from Maharashtra, Madhya Pradesh, Kerala and Tamil Nadu and classified it as a 'variant of interest'.
Indian SARS-CoV-2 Genomic Consortia (INSACOG), an Indian consortium of 28 labs established by the Ministry of Health & Family Welfare, said that SARS-CoV-2 virus causing COVID-19 disease is mutating continuously with an increase in the number of infections both across the world and in India. INSACOG is tasked with not just the whole genome sequencing, but also with giving timely inputs on appropriate public health response measures to be adopted by the states.
It said that mutations help the virus to become either more transmissible or more virulent or both. With time these mutations known as Variants of Interest (VOI) increase in frequency in the selected population and are considered then as Variants of Concern (VOC).
INSACOG had on June 18 reported the evolution of Delta Plus variant (B.1.617.2) + K417N lineage of SARS-CoV2 (called as B.1.617.2.1/ AY.1). The variant [(B.1.617.2.1/ (AY.1)] is characterized by the K417N mutation in Spike protein. 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 the spike protein.
There are other Delta plus variants with other mutations. However, 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.
All Delta sub-lineages are treated as a 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. World Health Organisation has introduced a classification 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 Ministry said that as of now among the samples sequenced (45000+) in India, this variant has been observed sporadically in Maharashtra, Kerala & Madhya Pradesh, with around 40 cases identified so far and no significant increase in prevalence. These states have been advised for strengthening surveillance and appropriate public health measures.
As of June 18, 205 sequences of AY.1 lineage was detected worldwide, with US and UK having over half the known cases, it said.
"Currently the number of such Delta plus variants in India are only a few but the distribution/detection in various States during past two+ months indicate that the B.1.617.2.1 (AY.1) is already present in some states and states may need to enhance their public health response by focusing on surveillance, enhanced testing, quick contact-tracing and priority vaccination in defined geographies where AY.1 has been detected," it said.