The World Health Organisation is working with researchers around the globe to better understand the new coronavirus variant after health experts in South Africa, where omicron was first detected, said it appeared to cause only mild symptoms.
There’s no information to suggest that symptoms associated with omicron differ from those caused by other variants, the Geneva-based WHO cautioned Sunday. Some of the earliest reported infections occurred among college students who are more likely to experience less severe illness from Covid-19, and understanding the level of severity of the new strain “will take days to several weeks,” the WHO said.
“We don’t have enough data to determine vaccine effectiveness against omicron or disease severity, so any claims about either at this stage are not evidence-based,” said Raina MacIntyre, professor of global biosecurity at the University of New South Wales in Sydney. “So far, the virus has not mutated to become less severe — in fact the opposite.”
Governments around the world are banning travelers from South Africa and nearby countries amid fears the new “variant of concern” could evade vaccines, exacerbate Covid surges and frustrate efforts to reopen economies. While news of the new variant wreaked havoc in global markets on Friday, trading in Asia Monday indicated investors were waiting for more clarity, as scientists from the US to Asia work to understand more about omicron’s makeup, its transmissibility, and how lethal it is compared with other strains.
The UK government will convene an urgent meeting of Group of Seven health ministers Monday to discuss the latest developments, according to the country’s Department of Health. In the US, President Joe Biden will also give an update on Monday, the White House said.
Omicron was first detected earlier this month. It’s characterised by some 30 genetic changes, half of which are in the receptor binding domain — the part of the spike protein used to bind to human ACE-2, which is the enzyme the coronavirus targets to enter cells and cause an infection. Mutations there can make the spike protein less recognizable to the antibodies made in response to vaccination or a natural infection.
Angelique Coetzee, chair of the South African Medical Association, called symptoms associated with the variant at this point “different and so mild” compared with others she’d treated for the virus in recent months.
Coetzee, who first spotted what turned out to be the new variant, told the UK’s Telegraph newspaper that a number of healthy young men turned up at her clinic “feeling so tired.” About half were unvaccinated.
“What we are seeing clinically in South Africa and remember, I’m at the epicenter, that’s where I’m practicing, is extremely mild,” she said Sunday on the BBC’s “Andrew Marr Show.”
“We haven’t admitted anyone” to the hospital with the new variant, she said. “I spoke to other colleagues of mine, the same picture.”
Asked if authorities around the world were panicking unnecessarily, Coetzee said “yes, at this stage I would say definitely. Two weeks from now on maybe we will say something different.”
Experts elsewhere, however, followed the WHO in urging caution.
The variant’s genome contains “some concerning elements,” said Stephen Goldstein, an evolutionary virologist at the University of Utah in Salt Lake City. Their affect on vaccine effectiveness should be better known in the next couple of weeks, he said. Omicron also has some mutations near the so-called furin cleavage site of the spike protein that are associated with the increased transmissibility of both the alpha and delta variants.
“We’re starting to see cases pop up in other parts of the world, so it appears to be spreading quite quickly, which leads to concerns that it may be even more transmissible than delta, but it really is too soon to say,” Goldstein said in a Zoom interview.
The average number of daily cases in South Africa jumped to about 1 600 last week from about 500 the previous week and 275 infections in the week before that, President Cyril Ramaphosa said Sunday. The proportion of Covid tests coming back positive jumped to 9% from about 2% in less than a week. Only 36% of adults in South Africa are fully vaccinated.
Barry Schoub, chairman of South Africa’s Ministerial Advisory Committee on Vaccines, said there’s been no real uptick in hospitalisations. “The cases that have occurred so far have all been mild cases, mild-to-moderate cases, and that’s a good sign,” Schoub told Sky News on Sunday, adding that it was still early days and nothing was certain yet.
No unusual symptoms have been reported following infection with omicron and, as with other variants, some individuals are asymptomatic, South Africa’s National Institute for Communicable Diseases said Friday.
Two omicron cases detected in Australia and an initial one in Hong Kong occurred in fully vaccinated people who developed no apparent sign of illness. A 62-year-old man who was infected in a quarantine hotel in Hong Kong did develop symptoms. Both places require negative Covid tests for travelers to enter, however, indicating these infections may have been at an early stage.
The WHO said there was preliminary data showing a higher number of hospitalizations, “but this may be due to increasing overall numbers of people becoming infected, rather than a result of specific infection with omicron.”
The large number of mutations found in the omicron variant appears to destabilize the virus, which might make it less “fit” than the dominant delta strain, said Schoub.
“In a way, hopefully it won’t displace delta because delta we know responds very well to the vaccine,” he said.