“Omicron has an unprecedented number of spike mutations, some of which are concerning for their potential impact on the trajectory of the pandemic,” the WHO said in a Nov. 28 technical brief to its 194 members, which include the United States and China.
“The overall global risk related to the new variant [of concern] Omicron is assessed as very high,” it added later.
Still, WHO scientists are, like experts around the world, not sure whether Omicron actually presents a problem.
The primary questions relate to how transmissible the variant is, whether it can evade protection from vaccines and natural immunity, and whether it causes more severe disease than other variants, scientists say.
The strain “may be associated with immune escape potential and higher transmissibility. However, there are still considerable uncertainties,” member-states were told.
“We do know that this is a variant that has a lot of mutations. It does make you worry, therefore, that it’s a sufficiently different virus, that it might not respond as well to protection from the vaccines. But we don’t know that,” Dr. Francis Collins, head of the U.S. National Institutes of Health, said on “Fox News Sunday.”
In a separate statement, the WHO said “it is not yet clear whether Omicron is more transmissible.” The body also said that “it is not yet clear whether infection with Omicron causes more severe disease compared to infections with other variants.” The “limited” information available suggests there may be an increased risk of reinfection in people who have previously had COVID-19, the WHO said.
Aspects of Omicron are being studied by researchers in South Africa and other countries and they plan to share their findings as new updates are available.
Omicron was initially detected in Botswana and South Africa earlier this month.
Since then, cases have been identified in a variety of areas, including Hong Kong, Israel, and the United Kingdom.
Officials in Ottawa, Canada on Sunday night announced the first confirmed cases in the country. Both individuals had recently traveled from Nigeria, they said.
No cases have been identified in the United States, but government health officials are divided as to whether Omicron has arrived yet.
“We have no evidence that it is. So I’m on the fence about that,” Collins said on CNN.
The United States and many other countries have banned or curtailed travel from southern African countries in response to Omicron.
U.S. President Joe Biden called it “a precautionary measure until we have more information.”
“Travel restrictions may play a role in slightly reducing the spread of COVID-19 but place a heavy burden on lives and livelihoods,” the WHO said.
