Peak of Alberta's 4th wave could hit 1,500 hospitalizations, modelling warns

New COVID-19 cases in Alberta could climb to 6,000 per day by the beginning of October, according to new virus modelling from a non-government group. 

'The worst is yet to come,' says UVic physics professor

Reports from the B.C. COVID-19 Modelling Group projects the delta-driven fourth wave could result in more than 6,000 new cases per day by October. (Jeff McIntosh/The Canadian Press)

New COVID-19 cases in Alberta could climb to 6,000 per day by the beginning of October, according to new virus modelling from a non-government group. 

That projection is part of an ongoing series of reports from the B.C. COVID-19 Modelling Group — a project run by various academics working in epidemiology, mathematics and data analysis. 

Their latest report, released Wednesday, warns that with the current relaxed health restrictions and stagnating vaccination rates, the delta-driven fourth wave could result in more than 6,000 new cases every day in about a month, with more than 1,500 hospitalizations and approaching 500 people in ICU. 

It's an addition to the group's August modelling that projected a peak of fourth wave cases at 17,500 per day by midway through the fall — accompanied by the potential for 5,500 people in hospital and around 1,000 in ICU. 

"The worst is yet to come," said Dean Karlen, one of the contributors and a physics professor at the University of Victoria. 

"How large the infection rate gets depends on actions by individuals, but also by governments." 

While it's very unlikely Alberta will confront the worst-case scenario (the report says this modelling gives enough warning time to take appropriate mitigation measures), Karlen says the window for action is closing. 

"We're following that rapid path, and at some point, action will be necessary to avoid that very outcome."

The report's projections

The report outlines different scenarios: One with no interventions at the current vaccination rate (that's the 6,000 daily cases) and one with the vaccine rate increasing and public health measures reintroduced. The model is built showing a slow increase in immunity, mimicking the waiting period between doses and the time it takes to have them take effect.

September's update projected that health measures and increased vaccination could result in about 3,000 daily cases in early October, with around 1,200 hospitalizations and about 250 in ICU.

About 70 per cent of eligible Albertans are fully vaccinated. 

Craig Jenne, an infectious diseases expert at the University of Calgary and member of the Snyder Institute for Chronic Diseases, says the group's modelling almost perfectly predicted the late summer COVID-19 numbers in Alberta  — and that should be a signal.

The B.C. COVID-19 Modelling Group says the above graph shows how the proportion of COVID cases of unknown origin has increased in line with the rollout of vaccination in Alberta. (B.C. COVID-19 Modelling Group)

"It gets pretty concerning before we even get to October with perhaps the reaching or exceeding hospital and ICU capacity," he said. 

Strain is being felt in some Alberta hospitals as a result of COVID-19 and staffing challenges. There were 44 ICU beds available out of 200 at the end of August, according to Alberta Health Services. About 44 per cent of capacity is being used for COVID patients. About 91 per cent of non-ICU capacity is also in use; five per cent are people with the virus. 

"It's likely that the health-care systems are going to be under severe duress in the coming weeks. And that's almost unavoidable," Karlen said of the situation.

Both experts said vaccinations will make the difference in heading off the projected October peak. 

"If we can get vaccination up higher, we would be less reliant on masks and less reliant on perhaps capacity limits. And that really gets us back as close as we can or closer to fully normal," Jenne said.

Alberta has not yet made up enough ground on vaccines to ease the push, Karlen said.

"The level of vaccination now is not sufficient to live in the current environment of transmission." 

The report says non-vaccine measures are needed to protect the public while officials work to increase vaccination rates. Masking, social distancing and air filtration are listed as suggestions. 

CBC News has reached out to the province asking about its own modelling and for reaction to this report.

Alberta delayed removing contact tracing and isolation protocols until Sept. 27 after the chief medical officer said virus trends prompted her to hit pause. The province has not indicated it intends to reinstate any restrictions lifted this summer. 

Stopping the projections from becoming reality will require provincial action and individuals buying into those policies, the two experts said.

"The message, I think, is that the province can't continue on this path for very much longer," Karlen concluded.  


  • An earlier version of this article referenced modelling that projected 17,500 cases by mid-October. In fact, more recent modelling lists the projection at 6,000 cases by the beginning of October.
    Sep 01, 2021 8:46 PM MT