The Delta variant, also referred to as a "double mutant" because it carries two mutations and is rapidly becoming the dominant strain of coronavirus globally.
Africa has reported many new outbreaks of the variant in Tunisia, Mozambique, Uganda, Nigeria and Malawi. In Europe, the Delta variant is spreading widely in France, Germany, Italy and Portugal.
According to the US Center for Disease Control and Prevention, the Delta variant is 60% more transmissible than the Alpha variant and causes more severe symptoms, especially in those who have not been vaccinated.