Ending the COVID-19 pandemic: We still have a long way to go.

Spread of the severe acute respiratory syndrome coronavirus 2 B.1.1.529 (Omicron) variant, which led to increased global hospitalizations for coronavirus disease 2019, generated concern about immune evasion and the duration of protection from vaccines, and undermined humanity's confidence in ending the epidemic. The sudden mutation and origin of Omicron is even more of a mystery. The article highlights the virological characteristics and possible origins of Omicron and the global threats and challenges it poses, as well as strategies to deal with it.