What is Delta variant of Covid and which group is most at risk?

The highly contagious Delta variant of the coronavirus is the ‘greatest threat’ to world’s attempt to eradicate the Covid-19 pandemic, leading health experts have predicted. White House Chief Medical Advisor Dr Anthony Fauci has warned that the variant, which was first detected in India, is more contagious and causes more severe disease than other circulating variants. Watch the video to understand Delta variant of Covid and whether it could trigger third wave in India.