Report: After data displayed minimal effectiveness, government pauses vaccine rollout
South Africa will put on hold use of AstraZeneca’s Covid-19 shot in its vaccination program, after data showed it gave minimal protection against mild-to-moderate infection caused by the country’s dominant coronavirus variant, Reuters reported.
South Africa Health Minister Zweli Mkhize noted yesterday that the government would await advice from scientists on how to proceed, after a trial displayed the AZ vaccine did not significantly reduce the risk of mild or moderate Covid-19 from the 501Y.V2 variant that caused a second wave of infections beginning late 2020.
Before widespread movement of the more contagious variant, the vaccine was showing efficacy of around 75%, researchers said, according to the report.
In a later analysis mainly based on infections by the new variant, there was only a 22% lower risk of developing mild-to-moderate Covid-19 versus those given a placebo. Although researchers said the figure was not statistically significant, due to trial design, it is well below the benchmark of at least 50% regulators have set for vaccines to be considered effective against the virus.
The study did not account for whether the vaccine helped prevent severe Covid-19 because it involved mostly relatively young adults not considered to be at high risk for serious illness.
South Africa hopes to vaccinate 40 million people, or two-thirds of the population, to achieve some level of herd immunity, but has yet to administer a single shot as of press time. It was originally aiming to roll out the AZ vaccine to healthcare workers soon after receiving 1 million doses produced by the Serum Institute of India (SII) earlier today. Rather, Reuters notes, South Africa will offer healthcare workers vaccines developed by Johnson & Johnson and Pfizer/BioNTech in the coming weeks.
UPDATE
Following publication, Reuters has since reported that South Africa could instead roll the AstraZeneca vaccine out in a “stepped manner,” distributing 100,000 doses and closely monitoring it to see if it prevents hospitalizations and deaths.