The earliest documented COVID-19 case caused by the delta variant (B.1.617.2) was first found in the Indian state of Maharashtra back in October 2020, and has since then spread widely throughout India and across the world. The World Health Organization (WHO) labelled it a “variant of concern” (VOC) on May 11.
So far, the WHO has identified four VOC: alpha (B.1.1.7), beta (B.1.351), gamma (P.1) and delta.
The delta variant has multiple mutations. Scientists don’t know the exact function of these mutations at this point in time but they are associated with allowing the virus to bind to the cells of humans and helping the virus to escape some immune responses, said Deepti Gurdasani, a clinical epidemiologist at Queen Mary University of London.
The delta variant is widespread and has been detected in more than 80 countries so far, according to the WHO. In the UK, tens of thousands of cases have been detected, according to the global science initiative GISAID, which is the highest number of identified delta cases in a country so far.