FILE Ñ A health care worker is given the Johnson & Johnson COVID-19 vaccine at an assembly hall on the grounds of Charlotte Maxeke Johannesburg Academic Hospital in Johannesburg, South Africa, March 5, 2021. A concerning new variant of the coronavirus, whose mutations evidence a Òbig jump in evolution,Ó is driving a spike in new COVID-19 infections in South Africa, scientists said on Thursday, Nov. 25. (Joao Silva/The New York Times)
