Two South Africans share their journey taking part in a Covid-19 vaccine trial

Robyn Porteous, 33, has been getting a phone call every month for the past year from a healthcare worker to check up on her. It's part of the routine she signed up for.

Porteous, an activist and writer in Johannesburg, is one of 2 070 South Africans who enrolled to be part of the Covid-19 Vaccine Trial in South African adults with and without HIV infection.

In the same boat as Porteous is 25-year-old second-year law student Tasneem Kathrada, who also volunteered to participate in the local Covid-19 vaccine trial.