The decision to classify Omicron as a variant of concern was based on the evidence presented to the WHO’s Technical Advisory Group on Virus Evolution.
This evidence suggested the new variant has several mutations that could impact how easily it spreads, the severity of illness it may cause and, crucially, the effectiveness of existing COVID-19 vaccines.
The WHO says it’s not yet clear if the Omicron variant is spread from person-to-person more easily than other variants, including Delta.
The number of people testing positive for COVID-19 has risen in the area of South Africa where Omicron was first identified. More research is being carried out to determine whether this is due to Omicron, or to other factors.
Early data from South Africa shows the rate of hospitalization is rising among COVID-19 patients. However, there is no evidence so far that directly links infection with Omicron with an increased need for hospital treatment.
The WHO says the rise in hospitalizations may be due to a general rise in infection rates. Many of the early Omicron cases reported in South Africa were among students.
With other COVID-19 variants, younger people have generally had milder symptoms. There is currently no evidence to suggest Omicron symptoms are different, but it will likely take weeks to determine if Omicron causes more severe illness among the general population.
