South Africa is finalising the sale of 1-million doses of the AstraZeneca vaccine to the African Union.

The sale will come cheap, Health Minister Zweli Mkhize has revealed.

Mkhize addressed the National Press Club on Thursday. He told the briefing local scientists were still working on research regarding the efficacy of the vaccine.

"We had ordered 1.5-million vaccines and discovered (later) that there were challenges that needed to be looked at. Our scientists are still researching them. In the meantime, we have offered 1-million of them to the African Union (AU) platform.

"The AU will buy it (from South Africa) at the same cost we spent at the Serum Institute (of India). Our legal team are finalising the agreement between us and the AU before they are released to various countries," Mkhize said.

Mkhize assured the attendees the AstraZeneca vaccine had not been used in South Africa.

"We are only going to use them once we get a clear guide from our scientists. Some African countries don't have the variant that we have here, and they can still utilise the AstraZeneca."

Mkhize added that they are not resting on their laurels after seeing a rapid decline in the number of Covid-19 cases.

"From 20 000 reports that we received a day, we [now] get about 1 000 and 1 500 a day. Those numbers are still high. We are also looking at the positivity rate, including how many people out of 100 are testing positive.

"The numbers are going down. We must continue with containment measures, including wearing of masks, sanitising of hands and social distancing. We remain vigilant to see if there are any changes and if another resurgence is coming."

Mkhize said by Wednesday evening about 82 000 healthcare workers had been vaccinated.

He said the number is above the government's target and it wants to see many more healthcare workers being vaccinated.