Omicron seems to have a growth advantage, WHO experts explained in a new document, while analyzing current data available, considering them still limited.
Omicron variant is currently spreading faster than Delta in South Africa, where this was low circulation, but also faster in other high Delta countries such as UK, they warned.
It remains uncertain whether the rapid rate of Omicron increase observed in nations with high levels of population immunity is related to immune evasion, increased intrinsic transmissibility or a combination of both, they explained.
There is currently little data on clinical severity of the strain, they added, “although preliminary results from South Africa suggest Omicron may be less severe than Delta”.
All cases reported in Europe to date have been mild or asymptomatic, while it remains unclear to what extent Omicron may be inherently less virulent, the document stressed.
More data is needed to understand the severity profile, the specialists explained, recalling there is no peer-reviewed evidence on the effectiveness of the vaccine against the new strain.