Preliminary evidence indicates that COVID-19 vaccines may be less effective against infection and transmission linked to the Omicron coronavirus variant, which also carries a higher risk of reinfection, the World Health Organization said on Wednesday.
The WHO, in its weekly epidemiological update, said that more data was needed to better understand the extent to which Omicron may evade immunity derived from either vaccines or previous infection.
"As a result of this, the overall risk related to the new variant of concern Omicron remains very high," it said.