A team of Canadian academics who monitor coronavirus variants are predicting a small bump in COVID-19 infections this spring, but they don’t see signs of major evolutionary changes in the virus that would alter the course of the pandemic the way Omicron did when it emerged in late 2021.
The experts at the Coronavirus Variants Rapid Response Network, or CoVaRR-Net, say their analysis mostly points to COVID cases and hospital admissions plodding along at the same steady but higher-than-ideal pace that has characterized the past eight months of the pandemic.
“The current modelling suggests that it’s going to continue at this sort of relatively high level as people have waning immunity and as these variants adapt,” said Fiona Brinkman, a professor of genomics and bioinformatics at Simon Fraser University.
Dr. Brinkman is the deputy leader of a CoVaRR-Net group that uses computer modelling to track the genetic evolution of SARS-CoV-2, the virus that causes COVID-19, and tries to predict how quickly new variants will spread in Canada.
The Omicron sublineage XBB.1.5 is responsible for most of the cases in Canada right now, Dr. Brinkman said, but she and her colleagues are keeping an eye on a relative called XBB.1.16 that appears to have a growth advantage over today’s predominant variant.
The good news is that the XBB family of variants doesn’t represent a significant evolutionary jump in the virus, Dr. Brinkman added. The bad news is that the XBB variants are immune-evasive enough to prevent COVID cases from falling off a cliff in the summer, as happens with seasonal respiratory viruses such as influenza and respiratory syncytial virus.
“It’s an interesting time in COVID world,” said Lisa Barrett, an infectious-diseases specialist at Dalhousie University. Most people are eager to move on and treat COVID as a run-of-the-mill seasonal virus, “only it really hasn’t become seasonal yet. It’s not really going away in between. There is no in-between yet.”
Dr. Barrett sees the staying power of COVID in her front-line work. She was reviewing an order for the antiviral Remdesivir for a COVID patient on Thursday in the emergency department of the Halifax Infirmary Hospital, part of the Queen Elizabeth II Health Sciences Centre, right before an interview.
Dr. Barrett said COVID is much less of a burden on hospitals today than it was last year or the year before, during the most punishing waves of the pandemic. But the virus is still sending enough elderly and immunocompromised people to hospital to affect a system that is also struggling with staffing shortages and daunting backlogs of surgery and other care.
Isaac Bogoch, an infectious-diseases specialist at the University Health Network in Toronto, is seeing something similar in Ontario. COVID-related hospital admissions are on the decline this spring – despite there being next-to-no public-health restrictions in place to curb the spread. “ICUs are not even remotely close to being overwhelmed with COVID-19. … We’re just not seeing the degree of illness we once saw.”
“Yes, it’s different and it’s better now,” Dr. Bogoch added. “But no, it doesn’t mean that it’s over. And this will continue, sadly, to prey upon medically vulnerable individuals for the foreseeable future.”
More than 52,000 Canadians have died of COVID-19, according to the Public Health Agency of Canada, which continues to track deaths and hospital admissions linked to the pandemic virus. The agency’s latest data show that 3,350 hospital beds were occupied by COVID-positive patients in early April, a significant drop from November, when, on some days, more than 6,000 beds were filled with people with COVID.
There remains some uncertainty about how many of those patients were admitted because of COVID as opposed to with incidental infections discovered when they were swabbed upon being admitted to hospital for something else. Public Health encourages the provinces and territories to report cases admitted to hospital as a result of COVID-19 illness, but recognizes that practices vary from province to province, a spokeswoman for the agency said by e-mail.
Dr. Brinkman of CoVaRR-Net urged policy makers to prioritize improving ventilation as one way of reducing the burden of COVID without reintroducing any public-health restrictions. She also urged elderly and immunocompromised patients who qualify for spring boosters to get their extra doses.
CoVaRR-Net researchers predict that if Canadians doubled the rate at which they get vaccinated, COVID-19 cases would decline by about 40 per cent, despite the shots not working as well against infection with the current variants as they did against those that preceded the rise of Omicron.
Kelly Grant