On December 28, 2021, President Biden released a presidential proclamation which eliminated temporary COVID-19 restrictions on entering the U.S. after travel from Botswana, Eswatini, Lesotho, Malawi, Mozambique, Namibia, South Africa, & Zimbabwe.
The COVID-19 vaccination entry requirements and testing restrictions, effective November 8, 2021, are still in place.
See this ISSS Frequently Asked Questions (FAQ) webpage for details about this current restriction.