Proof of Yellow Fever vaccination is not required for any of these since we will not be entering any of these from a place at high risk. Otherwise, looks like the usual vaccinations are recommended and anti-malarial if one wishes.
SOUTH AFRICA
https://wwwnc.cdc.gov/travel/destinations/clinician/none/south-africa
ZIMBABWE
https://wwwnc.cdc.gov/travel/destinations/clinician/none/zimbabwe
BOTSWANA
https://wwwnc.cdc.gov/travel/destinations/clinician/none/botswana#vaccines-and-medicines