The Delta variant of the coronavirus is dominant among global virus samples, but the Omicron variant is increasing and poses a risk, according to the World Health Organization’s newest weekly epidemiological report, published Tuesday.
In a section of the report on the spread of variants of concern, the organization said 96% of samples sequenced globally were Delta, down from 99.2% the previous week, and 1.6% were Omicron, up from 0.4% the previous week.
According to WHO data, the Omicron variant has been confirmed in 106 countries.
“Recent evidence indicates that Omicron variant has a growth advantage over the Delta variant and is spreading rapidly, even in countries with documented community transmission and high levels of population immunity,” the organization said.
Data on severity is limited, but hospitalizations are rising in the UK and South Africa.
“Given rapidly increasing case numbers, it is possible that healthcare systems may become overwhelmed. Preliminary data suggest that there is a reduction in neutralization of Omicron in those who have received a primary vaccination series or in those who have had prior SARS-CoV-2 infection, which may suggest a level of humoral immune evasion,” the organization said.
Because of these factors, “the overall risk related to the new variant of concern Omicron remains very high.”