The variant’s rapid spread, different vaccine strategies and varying levels of immunity worldwide make the pandemic’s future difficult to model.
On 11 January, just seven weeks after the Omicron variant was first reported, the World Health Organization (WHO) warned of a “tidal wave” of infection washing from west to east across the world. Fifty of the 53 countries in Europe and central Asia had reported cases of Omicron, said Hans Henri Kluge, the WHO’s regional director for Europe.