Omicron Variant, in at Least 20 Nations, Spread Earlier Than Was Known

Omicron Variant, in at Least 20 Nations, Spread Earlier Than Was Known
By Richard Pérez-Peña from NYT World https://ift.tt/3phWnqO
Coronavirus Omicron Variant, Coronavirus (2019-nCoV), Travel Warnings, South Africa, Europe, World Health Organization, Centers for Disease Control and Prevention, Vaccination and Immunization