Policemen and staff workers get tested for the coronavirus disease at a makeshift nucleic acid testing centre inside barriers of an area under lockdown in Shanghai, China March 24, 2022. [Reuters]
A sub-variant of the highly transmissible Omicron version of coronavirus known as BA.2 is now dominant worldwide, prompting surges in many countries in Europe and Asia and raising concern over the potential for a new wave in the United States.