Covid: First data points to Omicron re-infection risk
By James Gallagher
WHO's top scientist says Omicron could displace Delta
By Stephanie Nebehay & Francesco Guarascio
WHO says Covid omicron variant detected in 38 countries, early data suggests it's more contagious than delta
By Spencer Kimball
WHO says Omicron in 38 countries, no deaths reported
By Ted Regencia, Arwa Ibrahim & Elizabeth Melimopoulos