A COVID-19 patient is hospitalized in Amazon state, Brazil, on January 14, 2022. (Photo: AFP/VNA)

Omicron has rapidly overtaken Delta as the world's dominant COVID variant because it is more transmissible, though it appears to cause less severe illness. In an age of effective vaccines, half a million people dying, is really something, said Mahamud.

Maria Van Kerkhove, the WHO’s COVID-19 technical lead, said the number of COVID-19 cases is beyond tragic, but the real number may be far higher than reported. Many countries have not gone through the peak of Omicron yet, she said, noting her concern over rising deaths in recent weeks. This virus is still quite dynamic, Kerkhove warned.