The highly infectious Delta variant (B.1.617.2) of Covid-19 that first surfaced in India is feared to have mutated into a more virulent version called AY.1 or Delta Plus — one that is possibly capable of resisting even the monoclonal antibodies cocktail currently being prescribed as a cure.


  1. The new Delta plus variant has been formed due to a mutation in the Delta or B.1.617.2 variant.
  2. It is not yet a variant of concern (VoC) in India, due to low incidence.
  3. One of the emerging variants is B.1.617.2.1 or AY.1 is characterized by the acquisition of K417N mutation.
  4. The mutation is in the spike protein of SARS-COV-2, which helps the virus enter and infect the human cells.
  5. 63 genomes of Delta (B.1.617.2) with the new K417N mutation have been identified by the GISAID so far.
  6. Delta plus was present in six genomes from India as of 7 June 2021, as per Public Health England (PHE).
  7. The variant frequency for K417N is not much in India at this point in time. The sequences are mostly from Europe, Asia and America.