It's not really complicated. The link shared by @ForceFate details the process. According to the article "Trials cannot be conducted, and medicines cannot be prescribed, sold or marketed in South Africa, without prior SAHPRA approval"Thankfully you're not in charge.
And do tell how the approval process looks... I'm keen to hear your take on how it should go.
I assume you think we get test sample freebies because Nelson Mandela was born here.
So government can get hold of as many doses of the vaccine as they like, but according to the law they cannot give out the vaccine until the SAHPRA has approved it. Right now SAHPRA has not approved any vaccine. This should be simple to understand.