Why did the WHO "raise the alarm" about omicron?

As stated, this strain is likely to spread around the world, and a larger increase in the number of infected could have severe consequences in some areas.
Although it is not yet known to what extent omicron is contagious for those who have been vaccinated and recovered from COVID-19, the WHO recommends accelerated vaccination of risk groups.
"Cases of COVID-19 are also expected in vaccinated persons, but in a small and predictable part," WHO experts predict.
This institution gave recommendations to the states to work on preparations with intensive immunization, in order to preserve the necessary health services, despite the expected increase in the number of infected people.
The WHO reiterated that the omicron strain has numerous mutations on the spike protein, which is the "target" of the vaccine.
"We epidemiologists interpret this alert of the World Health Organization (WHO) as a call for precaution, as well as a call to monitor the spread of the new variant of omicron. We only know about the new variant for a week and a lot is unknown to us... Based on information from the South Africa, it is obvious that the number of hospitalizations has increased there, but that the clinical picture of patients is not difficult", says epidemiologist Branko Kolari, as reported by Jutarnji list.
Kolari points out that although omicron has as many as 32 mutations in the spike protein compared to the original strain from Wuhan, it is still the same virus.