Healthcare worker walks past a poster explaining the after effects of the Johnson & Johnson COVID-19 vaccine at a vaccination centre at Chris Hani Baragwanath Academic Hospital in Johannesburg, South Africa, Friday, March 26, 2021. (AP Photo/Themba Hadebe)

FILE — In this Friday, March 26, 2021 file photo, healthcare workers queue to receive a dose of Johnson & Johnson COVID-19 vaccine at a vaccination centre at Chris Hani Baragwanath Academic Hospital in Johannesburg, South Africa. In a television address to the nation Tuesday, March 30, 2021, Presidential Cyril Ramaphosa outlined the progress and the future of the COVID-19 vaccine rollout and put in place some minor restrictions for the Easter weekend. (AP Photo/Themba Hadebe, file)

Khensani Chauke, a professional paramedic, receives a dose of Johnson & Johnson COVID-19 vaccine from a health staff member during a vaccination day for healthcare workers at a vaccination centre at Chris Hani Baragwanath Academic Hospital in Johannesburg, South Africa, Friday, March 26, 2021. (AP Photo/Themba Hadebe)