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people with omicron much more likely to be asymptomatic, research suggests

'as we witness the quick, global spread of omicron, it is clear that we urgently need a better understanding of the transmission dynamics of this variant,' says lead study author.

by maija kappler

jan 10 2022

2 minute read

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people with omicron much more likely to be asymptomatic: new research

on monday, health canada reported 25,466 new covid cases. getty

people infected with the omicron variant of the virus that causes covid are more likely to be asymptomatic than people who got sick with another variant, according to two new clinical trials. the finding could help explain the worldwide spike in covid cases since omicron was first identified in november.

one of the studies looked at 577 south african healthcare workers who were fully vaccinated with the single-dose johnson & johnson vaccine and found that 2.6 per cent of people infected with the beta and delta variants had no symptoms. but in people infected with the omicron variant, asymptomatic infections rose to a staggering 16 per cent.

the other study , a vaccine trial studied 230 people living with hiv in east and southern africa — all had received the moderna vaccine. of the 71 participants who tested positive for covid and were later confirmed to have the omicron variant, 27 per cent were asymptomatic. a previous portion of the study, which had looked at people in the same region during south africa’s beta outbreak, had found an asymptomatic rate of between one and 2.4 per cent.

“as we witness the quick, global spread of omicron, it is clear that we urgently need a better understanding of the transmission dynamics of this variant,” dr. lawrence corey, senior author of the study, said in a press release .

because the data is part of an ongoing study, it has not yet been peer-reviewed.

the south african study is one of several aiming to discover how and why the newest variant spreads so rapidly. omicron appears to be much more contagious than previous variants, even among people who are fully vaccinated. (vaccinated people, though, don’t risk hospitalization or death as a result of covid infection at rates anywhere near unvaccinated people who get infected: in ontario, one fully vaccinated person out of every million ends up in the icu , compared to 153 unvaccinated people.) a recent danish study suggested it may be due in part to the way the virus can elude our immune systems.

lack of covid tests

part of what increases transmissibility is a lack of access to tests in canada and elsewhere. the virus can easily spread among people who don’t realize they’re sick — especially if, as the south african study suggests, they’re asymptomatic.

“i think we’re in crisis,” epidemiologist and university of ottawa professor raywat deonandan told global news . “people cannot get pcr tests. the rapid tests are hard to find as well. so we’re at the stage where we’re probably rationing pcr tests to a large extent, by which i mean reserving them for health-care workers or people who need them for clinical diagnostic purposes.”

on monday, health canada reported 25,466 new covid cases .

maija kappler is a reporter and editor at healthing. she can be reached at mkappler@postmedia.com

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people with omicron much more likely to be asymptomatic, research suggests

'as we witness the quick, global spread of omicron, it is clear that we urgently need a better understanding of the transmission dynamics of this variant,' says lead study author.

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people with omicron much more likely to be asymptomatic, research suggests

'as we witness the quick, global spread of omicron, it is clear that we urgently need a better understanding of the transmission dynamics of this variant,' says lead study author.

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