South Africa will suspend 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.

Health Minister Zweli Mkhize said on Sunday the government would await advice from scientists on how best to proceed, after disappointing results in a trial conducted by the University of the Witwatersrand.

The government had intended to roll the AstraZeneca shot out to health-care workers soon, after receiving 1 million doses produced by the Serum Institute of India on Monday.

Instead, it will offer vaccines developed by Johnson & Johnson and Pfizer in the coming weeks while experts consider how the AstraZeneca shot can be deployed.

“What does that mean for our vaccination program which we said will start in February? The answer is it will proceed,” Mkhize told an online news briefing.

“From next week for the next four weeks we expect that there will be J&J vaccines, there will be Pfizer vaccines. So what will be available to the health workers will be those vaccines.”

“The AstraZeneca vaccine will remain with us … up until the scientists give us clear indications as to what we need to do,” he added.