SOWETO, SOUTH AFRICA – JUNE 26: A medical worker holds a bottle during the country’s first human clinical trial for a potential vaccine against COVID-19 at the Baragwanath Hospital on June 28, 2020 in Soweto, South Africa. It is reported that Africa’s first COVID-19 vaccine trial began on June 24 in South Africa. The vaccine, developed by Oxford University’s (UK) Jenner Institute, will inoculate two thousand South Africans. (Photo by Felix Dlangamandla/Beeld/Gallo Images via Getty Images)