Volunteers wait to be checked at a vaccine trial facility set at Soweto's Chris Sani Baragwanath Hospital outside Johannesburg, South Africa, November 30, 2020. 

Volunteers wait to be checked at a vaccine trial facility set at Soweto's Chris Sani Baragwanath Hospital outside Johannesburg, South Africa, November 30, 2020. 

© 2021 AP Photo/Jerome Delay)