South Africa plans to kickstart its Covid-19 vaccination campaign with Johnson & Johnson jabs after withholding a batch of AstraZeneca doses following doubts over the shot's efficacy. The country worst-hit by the pandemic in Africa had suspended its vaccine rollout - meant to begin with OxfordAstraZeneca - after scientists found the shot failed to prevent mild and moderate illness caused by a local virus variant known as 501Y.V2.