Sandile Cele, a researcher at the Africa Health Research Institute in Durban, South Africa, works on the omicron variant of the COVID-19 virus Wednesday Dec. 15, 2021. South Africa's noticeable drop in new COVID-19 cases in recent days may signal that the country's dramatic omicron-driven wave has passed its peak, medical experts say. (AP Photo/Jerome Delay, File)

December 22, 2021