Where did you get that? It's not that people from S. Africa (or anywhere in Africa) cannot tolerate vaccines, a larger percentage of people from Africa are far more wary of vaccines than in most first world countries. Big difference.
Back in very late 2019/early 2020 the initial covid cases, outside of China, were in Italy. There is a large population of Chinese in Italy (estimates say over 300k) mostly for the work in garment factories. They go home to family in China for the Chinese new year.
There are Chinese everywhere...a perfect means to move an emerging virus around.
Many people in South Africa have compromised immune systems and many are advised not to take the vaccine because of that.