Kingston, Ont., posted 154 new cases of COVID-19 on Wednesday as its Omicron outbreak continued.
The eastern Ontario city of around 160,000 people was an early hotspot of the Omicron outbreak in Canada, with an early explosion of cases.
But at the Kingston Health Sciences Centre, the number of people hospitalized with COVID-19 has gone down recently, said Dr. Gerald Evans, an infectious diseases specialist at the hospital and with Queen’s University.
“So far at least, the effect of this increasing number of cases, most of which are Omicron, has not yet hit the hospitals,” he said.
Recent research is giving some health experts hope that people will stay out of hospital. Two new studies from the U.K. and one from South Africa suggest that a smaller percentage of people who catch Omicron might end up in hospital than with previous variants – though doctors say that even if that’s true, the health system could have a hard time keeping up.
For now, doctors are assuming that the percentage of patients who end up in hospital due to the Omicron variant will be similar to the percentage hospitalized with Delta, Evans said.
“If that’s the case, then these rising case numbers will mean that at least in a few more weeks, we’re likely to see increasing hospitalizations of individuals.”
This is already happening in Quebec, where hospital admissions are beginning to rise after days of record-breaking case numbers.
U.K. studies on Omicron severity
In the U.K., which is dealing with its own Omicron-fuelled wave of COVID-19, two recent studies suggest that people who catch Omicron might be less likely to be hospitalized than with previous variants.
An analysis from the Imperial College London COVID-19 response team estimated hospitalization risks for Omicron cases in England, finding people infected with the variant are around 20 per cent less likely to go to the hospital at all than those infected with the Delta variant, and 40 per cent less likely to be hospitalized for a night or more.
That analysis included all cases of COVID-19 confirmed by PCR tests in England in the first half of December in which the variant could be identified: 56,000 cases of Omicron and 269,000 cases of Delta.
A separate study out of Scotland, by scientists at the University of Edinburgh and other experts, suggested the risk of hospitalization was two-thirds less with Omicron than Delta. But that study pointed out that the nearly 24,000 Omicron cases in Scotland were predominantly among younger adults ages 20 to 39. Younger people are much less likely to develop severe cases of COVID-19, though even controlling for age, researchers still found a similar effect.
“This national investigation is one of the first to show that Omicron is less likely to result in COVID-19 hospitalization than Delta,” researchers wrote. While the findings are early observations, “they are encouraging,” the authors wrote.
How vaccines protect against the Omicron variant
U.K. hospitalizations “have gone up, but not hugely,” said Linda Bauld, a professor of public health with the University of Edinburgh.
That doesn’t mean it won’t happen, she said – she and her U.K. colleagues are projecting that the middle and end of January could still see a surge in hospitalizations.
But, she said, so far Omicron doesn’t seem to be causing as much severe illness. Partly, she thinks, that’s because many of the U.K. cases have been in younger people, who are less likely to end up in hospital with COVID-19. Also, she notes, hospitalization is a lagging indicator and could still catch up.
She thinks the lower hospitalization rate also has a lot to do with vaccines and previous COVID-19 infections. While the Omicron variant is better at infecting people who are vaccinated or who have some immunity from a previous infection, she said, those cases seem less likely to be severe.
“Probably the vast, vast majority of them will have had two doses, and they may well have had the second dose more than two or three months ago, where we know there is some waning,” she said.
However, these studies might show that these individuals “do have some protection,” she said.
Evans hopes the same.
“We know that even with two doses, there is an effect of offering some protection against severe outcomes, even against Omicron, so that’s in our favour at the moment,” he said.
Still, it’s “too early to tell” what Omicron’s impact will be on Canadian hospitals, Dr. Allison McGeer, an infectious diseases specialist at Toronto’s Mount Sinai hospital, said on Wednesday.
“We don’t expect people to be hospitalized until seven to 10 days post-onset and it is exactly seven days ago that Omicron exceeded Delta — not long enough to be able to tell.”
Hospitals’ ability to handle Omicron depends a lot on the overall case numbers, Evans said.
“When we modelled the case numbers at the Ontario Science Table a week or so ago, there’s a very broad range in terms of the total number of cases,” he said. “And at the very extremes, that would probably overload the ability of hospitals to maintain it, especially given that we’re stressed now by staffing issues because many of our staff are getting infected out in the community.”
It’s not just hospitals that could be affected, even if the virus isn’t causing lots of severe illness, Bauld said.
In the U.K., she said, staff absences are a concern in the health-care system and elsewhere.
“With such an infectious virus, and so many hundreds of thousands of cases, we are already seeing a major impact on our public services,” she said.
“We’ve had hundreds of train cancellations, for example, in Scotland over recent days, and we’re concerned about some of our essential services.”
Canada needs to keep handing out third doses of vaccine, she said, and consider reimposing some restrictions to avoid this.
— with files from The Associated Press