A new and slightly changed version of the Delta coronavirus variant is spreading in a number of countries including the United Kingdom, United States and India, health officials say. This strain, which has generated a significant amount of global media attention, is called B.1.617.2.1 or AY.1 -- Delta Plus for short, and is a version of the Delta variant first detected in India in February. It was first reported by Public Health England, a government health agency, on June 11. But the UK's first few cases had been sequenced on April 26 -- suggesting the variant may have been present and spreading by the spring.