South Africa announced this week that it’s stopping the use of the AstraZeneca-Oxford COVID-19 vaccine after a small study found that it wasn’t effective against mild and moderate disease. Other vaccines are also less effective in South Africa, where a variant of the virus with mutations that can dodge antibodies is circulating widely. The AstraZeneca-Oxford product appears to be the worst of all, and it fell down to less than 50 percent effective (the benchmark health agencies set for COVID-19 vaccines).
It’s another hit for the AstraZeneca-Oxford vaccine, which has been dogged by shaky relationships with regulators and limited transparency for months. But it’s also a confusing result: the small trial wasn’t able to figure out if the…