'Sputnik V is more efficient against the Delta variant of coronavirus'

New Delhi, June 15: Russia's Sputnik V is more efficient against the Delta variant of coronavirus, first detected in India than any other vaccine, reveals a study.

The study conducted by the Gamaleya Center was submitted for publication in an international peer-reviewed journal. Delta varaiant is blamed for the disastrous second wave of coronavirus infections in India.

The B.1.617 variant and its lineage B.1.617.2 were primarily responsible for the surge in cases. The Delta variant is said to have 50 per cent more transmissibility than the Alpha or B.1.1.7 variant.

The Delta variant has also led to several infections even among vaccinated individuals. Studies say "B.1.617.2 was over-represented and B.1.1.7 was not even detected in vaccination breakthroughs, suggesting higher breakthrough risk of B.1.617.2 compared to B.1.1.7."

The B.1.617 lineage has further evolved into three sub lineages -- B.1.617.1, B.1.617.2 and B.1.617.3. Early data shows B.1.617.2, dubbed Delta by the WHO, has higher transmission advantages over the other two sub-lineages.

B.1.617, initially termed a double mutant, has three new spike protein mutations. Two mutations -- E484Q and L452R -- are in the area important for antibody-based neutralisation.

The third mutation -- P681R in B.1.617 -- along with the reversion of E484Q allows its sub-lineage to be more infectious.

It was found in high levels in genomes sequenced in Maharashtra (2,077), West Bengal (630), Delhi (1,458), Karnataka (225) as of May 28, and accumulates new mutations in spike and other genes, the INSACOG found in the genomes sequenced as of May 28.

The World Health Organisation (WHO) has termed it a ''Variant of Concern''. B.1.617.1 and B.1.617.3 sub-lineages have two receptor binding domain mutations --- L452R and E484Q. The former has seven spike mutations, while the latter has seven to eight.

In the case of B.1.617.2, it has nine to 10 spike mutations and two receptor binding domain mutations --- L452R and T478K. B.1.6171.1 and B.1.617.2 have higher transmission rate and reduced susceptibility to neutralisation antibodies.

In the case of all the three sub-lineages, it has the potential to reduced antibody efficacy and potential reduced neutralisation by vaccine sera, which, however, remains to be established. B.1.1.7, also known as the Alpha variant, has 50 per cent increased transmission. It also has increased severity.