Johnson & Johnson’s single-dose Covid-19 vaccine has started to roll-out in South Africa. The shot is being administered as part of a research study that is targeting up to half a million healthcare workers and marks the first time the vaccine is being deployed outside of clinical trials...Johnson & Johnson’s single-dose Covid-19 vaccine has started to roll-out in South Africa. The shot is being administered as part of a research study that is targeting up to half a million healthcare workers and marks the first time the vaccine is being deployed outside of clinical trials... Johnson & Johnson Covid-19 Vaccine Updates: South African Roll-out, FDA Reviews