(CN) — The World Health Organization on Tuesday said the new omicron variant is the fastest spreading strain yet seen in the pandemic but that it is too early to know if it is also less severe.
Since the United Nations health agency announced the emergence of the new highly transmissible strain, omicron cases have been found in 77 nations and it has likely spread to most countries in the world, said Tedros Adhanom Ghebreyesus, the agency's director-general.
“Omicron is spreading at a rate we have not seen with any previous variant,” he said at a news briefing from the WHO's Geneva headquarters.
This strain was first detected in southern Africa and studies from South Africa suggest the highly mutated variant might cause a less severe infection, which would of course be a very welcome development because it is expected to quickly become dominant and replace the delta strain.
But the WHO warned against making light of its potential to cause severe disease.
“We're concerned that people are dismissing omicron as mild,” Tedros said. “Surely, we have learned by now that we underestimate this virus at our peril.”
He added that even if omicron proves to be more mild, the speed at which it is spreading will put many people at risk of hospitalization. He lamented the low rate of vaccination in many parts of the world, which he has blamed on richer countries hoarding stockpiles.
“Even if omicron does cause less severe disease, the sheer number of cases could once again overwhelm unprepared health systems,” he said.
To prevent a wave of disease, Tedros said countries need to continue rolling out vaccines and people, even the vaccinated, need to keep up preventive measures – such as mask wearing, hand washing and staying away from large gatherings.
Dr. Bruce Aylward, a WHO senior adviser, said much more data needs to be gathered and assessed to understand the threat posed by omicron. He said scientists are working to get a full picture on how it affects people of different ages and ethnicities and how well vaccines work against it.
In South Africa, the number of new infections has soared since omicron was identified in late November. Back then about 1,000 new infections were detected on average a day but now it is reporting more than 20,000 new cases a day, according to figures tracked by Worldometer. But the number of deaths is not spiking in conjunction with the high number of cases, the data shows, with South Africa recording about 25 deaths on average a day.
The concern, though, is that omicron infections will increase among more vulnerable populations and that vaccines may not be as effective against it due to the high number of novel mutations found in this variant.
On Monday, the United Kingdom reported its first omicron-linked death, a development that caused alarm. By Tuesday, the British parliament was in a heated debate over imposing new restrictions, including a requirement to show so-called Covid-19 passes to get into larger venues like nightclubs. A large number of British Prime Minister Boris Johnson's own party members opposed the new restrictions but the requirement ultimately passed.
In the U.K., omicron infections make up about 40% of new infections in London. “It's spreading at a phenomenal rate, something that we've never seen before, it's doubling every two to three days in infections,” Health Secretary Sajid Javid told Sky News.
Saying the question about whether omicron is more mild needs to be “set on one side,” Johnson argued the new measures were needed due to the “sheer pace at which it accelerates through the population.”
Dr. Mike Ryan, the WHO's emergencies chief, said countries must prepare for the worst.
“We need to be ready to deal with what is likely to happen, which is a large wave of cases, which may or may not be more or less severe but which in themselves generate pressure on the health system,” he said.
“We'll be the happiest people in the world to come back to you in two weeks’ time, or three weeks’ time, and say this is a much milder disease, everything is fine,” Ryan said. “But that is not how this virus has behaved up to now, that's not our experience through the three waves of this pandemic.”
Globally, more than 5.3 million deaths have been linked to Covid-19, the disease caused by the novel coronavirus.
Courthouse News reporter Cain Burdeau is based in the European Union.Follow @cainburdeau
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