The highly contagious Delta variant has become the dominant Coronavirus strain in the US, accounting for more than 51 per cent of Covid infections in the country, according to new data released by the Centres for Disease Control and Prevention. The variant, also known as B.1.617.2, was first detected in India in December and is spreading quickly across the globe. In some parts of America, the Delta strain accounts for more than 80 per cent of new infections, including some Midwestern states like Missouri, Kansas and Iowa.

It is already causing 74.3 per cent of infections in western states, including Utah and Colorado, and 58.8 per cent of infections in southern states like Texas, Louisiana, Arkansas and Oklahoma, according to CDC estimates.