Deal With Delta

The global dominance of the Delta variant shows that mutations have kept SARS-CoV-2 ahead of the game

- Vibha Varshney

Researchers HAD predicted that 2021 would become the year of variants. It has. Currently, there are four variants of concern, as per the World Health Organization (WHO), of which the Delta variant, implicated in India’s second wave of infections, has been reported from 124 countries and is set to become the most dominant variant circulating in the world.

The variant was first isolated in India in October 2020. On April 4, 2021, who labeled it a variant of interest, and on May 11, 2021, upgraded it to a variant of concern. In the UK, it forms 99.3 per cent of the sequenced samples in the four weeks preceding July 23 (see 'Fast-spreading variant', p18), while in the US, it is 73.7 per cent of the sequenced samples in the same period, as per the Global Initiative on Sharing Avian Influenza Data (GISAID), an online repository of genomic data from flu viruses.

Mutations have helped the virus dominate across the world. “Compared to the Wuhan strain, the Delta variant has nine mutations in the spike proteins that help the virus gain entry into the cell,” Olivier Schwartz, head of the Virus and Immunity Unit at Institut Pasteur, France, tells