LONDON – South Africa has decided against using the 1 million doses of Astrazeneca plc’s COVID-19 vaccine already in the country to start the rollout of its national vaccination program, in favor of opening a phase IIIb study of Johnson & Johnson’s single shot product. “Over the next few days, we expect to announce a plan to expedite vaccination using [J&J’s] investigational vaccine in health care professionals in South Africa,” said Glenda Gray, CEO of the South African Medical Research Council and chair of the country’s research committee on COVID-19.