“As of now among the samples sequenced (45000+) in India, this variant has been observed sporadically in Maharashtra, Kerala, and Madhya Pradesh, with around 40 cases identified so far and no significant increase in prevalence. After the report of AY.1 by PHE, a retrospective analysis of samples revealed the first occurrence of this lineage in a sample collected from Maharashtra. These States have been advised for strengthening surveillance and appropriate public health measures. As of 18th June, 205 sequences of AY.1 lineage were detected worldwide, with the USA and UK having over half the known cases. The mutation K417N has been of interest as it is present in the Beta variant (B.1.351 lineage), which was reported to have immune evasion property. The resistance to monoclonal antibody cocktail might not indicate increased virulence,” a statement from the Union Health Ministry said.
The ministry informed that 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.
The consortium informs that this viral variant has also been seen in nine other countries of the world. World Health Organisation (WHO) 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.
INSACOG reported that the evolution of the Delta plus variant (B.1.617.2) + K417N lineage of SARS-CoV2 (called 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 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. AY.1 is the most well-known, but these are not identical. A second clade found in sequences uploaded to GISAID from the USA is now designated AY.2, but is not seen in India yet,” the statement said.
Further informed 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. 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).
Mentioning the role of AY.1’s role, the statement informed that in immune escape, disease severity or increased transmissibility, etc. is under continued surveillance.
“Currently the number of such Delta plus variants in India are only a few but the distribution or detection in various States during past over 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,” the Union Health Ministry added.
Meanwhile, the experts have raised concerns about whether current vaccines will be effective against Delta Plus. The government has informed two vaccines being used in India, Serum Institute of India’s (SII) Covishield and Bharat Biotech’s Covaxin, are effective against the Delta variant, data on how they work on the Delta Plus would be shared later.