Why in News?

• Variant Delta (B.1.617.2), the most pervasive variant of the coronavirus in India, constituted nearly three in four breakthrough infections in Delhi, according to a research study by scientists in Delhi.

About the study

• Scientists found that two lineages dominated. B.1.617.1 (Kappa) comprised 8%, Delta was 76% and the remaining linked to variants that belonged to broader “B.1 lineages”.
• However, the international variant Alpha, which in previous studies has been associated with a spike in cases in Delhi earlier, was absent in vaccination breakthrough-cases analysed.
• The study also reports a new mutation in Delta called T478K that the scientists believe has a role to play in allowing the coronavirus to better infiltrate human cells.

Why is study important?

• To understand  vaccine effectiveness in India against various strains.
• And also assess the risk to various populations, by age, to decide on the dosage of vaccine

 Reference:

1. https://www.thehindu.com/news/cities/Delhi/delta-variant-led-to-most-post-vaccine-infections-in-delhi/article34730572.ece