Rollout of AstraZeneca COVID-19 vaccine halted in South Africa after study

Based on clinical trial results, which reveal a gap in protection against a new strain of coronavirus, health officials in South Africa for now are shelving plans to distribute AstraZeneca's vaccine. Although the study was too small to have statistical significance, data suggest the injection would be just 10% effective against mild and moderate COVID-19 linked to the highly transmissible mutation. Given the relatively young age and low risk for severe disease of the study participants, it is unclear if the vaccine works in more serious cases. South Africa, where the variant was initially detected, had planned to deliver 1 million doses to health care workers later this month. The rollout is now on hold as researchers return to the drawing board to reformulate the vaccine to fight new strains—a step also being taken by other vaccine manufacturers. AstraZeneca anticipates introducing a new vaccine by the fall. In the meantime, South African health minister Zweli Mkhize says the country will accelerate distribution of the Johnson & Johnson vaccine, which has yet to be authorized in the United States.