After data showed that it provided limited defence against mild to moderate infection caused by the dominant coronavirus variant of the region, South Africa will put on hold use of AstraZeneca's Covid-19 shot in its vaccination programme. After a study found that the AstraZeneca vaccine did not substantially reduce the risk of mild or moderate Covid-19 from the 501Y.V2 strain that triggered a second wave of infections beginning late last year, Health Minister Zweli Mkhize said on Sunday that the government will await advice from scientists on how best to proceed.
The vaccine showed efficacy of about 75 percent prior to widespread circulation of the more infectious version, researchers said. There was only a 22 percent reduction in risk of developing mild-to-moderate Covid-19 than those given placebo in a later study focused more on infections with the new version. Although the figure was not statistically significant due to the nature of the experiment, the researchers said that it is well below the benchmark set by at least 50 percent of regulators for vaccines to be deemed successful against the coronavirus. The study did not determine whether the vaccine helped to prevent severe Covid-19 disease since it mainly included relatively young adults who were not deemed to be at high risk of serious illness.