A trial showed the vaccine provides only “minimal” protection against mild to moderate Covid-19 caused by the variant first detected in South Africa, a setback to the global fight against the pandemic as many poorer nations are relying on the logistical advantages offered by the AstraZeneca shot.
South Africa suspended the start of its AstraZeneca inoculation programme over concerns the shot does not work on a new variant, with WHO experts due to meet Monday to discuss the vaccine already facing questions about its efficacy for over-65s.
Africa’s hardest-hit nation was due to start its campaign in the coming days with a million AstraZeneca doses but the government decided to hold off in light of the results from the trial conducted by the University of Witatersrand in Johannesburg.
“It’s a temporary issue that we have to hold on AstraZeneca until we figure out these issues,” Health Minister Zweli Mkhize told reporters on Sunday.
The 1.5 million AstraZeneca vaccines obtained by South Africa, which will expire in April, will be kept until scientists give clear indications on their use, he added.
AstraZeneca, which developed the shot with the University of Oxford, told AFP: “We do believe our vaccine will still protect against severe disease.”
A company spokesperson said researchers were already working to update the vaccine to deal with the South African variant, which has been spreading rapidly around the world.
A World Health Organization panel is due to meet on Monday in Geneva to examine the shot, which is a major component of the initial Covax global vaccine rollout that covers some 145 countries — mostly lower- and lower-middle income economies.
Out of the initial 337.2 million Covax doses, 240 million are AstraZeneca shots, which do not require the supercold storage needed for the Pfizer and Moderna vaccines.
There were already concerns about the efficacy of the AstraZeneca shot among over-65s, with a number of European nations not authorising it yet for that demographic.