COVID-19 modelling group sounds alarm over Alberta's case trajectory and emerging delta variant

A modelling team in British Columbia says Alberta is in a danger zone due to its COVID-19 trajectory and the emerging delta variant. 

The province recently announced a plan to relax its COVID-19 surveillance and management system despite an increase in case numbers, the positivity rate and R-value, and vaccination rates that are lagging behind other provinces.

As of Thursday, quarantine for close contacts became no longer mandatory but just recommended. Contact tracers will no longer notify close contacts, but they will continue to investigate cases in high-risk settings such as continuing care facilities. Asymptomatic testing will no longer be recommended.

Alberta announced 187 new cases of COVID-19 on Friday, with active case count of 1655. 

Dr. Theresa Tam, Canada's chief public health officer, said at a press conference Friday that every jurisdiction in Canada could have delta-driven waves if the vaccine rate does not go up as quickly as the relaxation of measures. 

"I firmly believe that quarantine and isolation can help prevent the spread of COVID-19, especially in light of the spread of the delta variant," she said.

Those who are diagnosed with COVID-19 are still recommended by Tam to isolate, despite Alberta saying it will stop mandating it by mid-August.

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"I think Alberta, like all provinces, is doing very well in trying to get their population vaccinated but still has a ways to go," she said.

Tam warned that Canada, as a whole, is at the start of a delta-driven fourth wave and predicts a sharp resurgence of cases by the end of summer if people's contacts continue to grow.

"It's not just about the fact that Alberta may have a delta-driven wave or the others [provinces] may well get in a similar position if the vaccine rate going up is not as fast as the relaxation of measures." 

Group projects spike in cases

Sarah Otto, a professor at the department of zoology at the University of British Columbia, is with a group that's been doing COVID-19 modelling for Alberta.

She says the projections are not looking good for the province.

"We've been seeing a rise in the proportion of delta cases and seeing that now lead to an uptick in cases in Alberta," she said.

The professor says Alberta could see an increase in hospitalization rates in the next two weeks, as well as hit a new high of cases by the end of August.

"The type of rate of spread that we're seeing is really fast. It's like doubling every eight to 10 days," she said.

And based on that data, Otto says they expected stricter health restrictions from the Alberta government, not the other way around.

"Alberta is a real danger zone because many, many people are unvaccinated, and with delta causing twice as many people who catch it to land in hospital and to die, this is a much more severe disease than what we were dealing with before, earlier in this year," she said.

"So this just seems like a total mismatch and really risks the health of citizens in Alberta."

Risk to the unvaccinated

Craig Jenne, an associate professor in the department of microbiology, immunology and infectious diseases at the University of Calgary and a Canada Research chair, says while Alberta's case count is a relatively small number than the third wave, the rate of growth is reason for concern.

"This is a virus that is moving very quickly through the province of Alberta right now," he told CBC Calgary News at 6. "The big concern is that this much spread means that it will be affecting unvaccinated Albertans, and those individuals do not have protection from severe illness."

He says the delta variant is more infectious than other variants, meaning it's more likely to impact individuals.

"People who are vaccinated can still catch delta and, critically, pass that on to individuals," he said, adding that it could also pose risk to kids under 12 who are not yet eligible for vaccination.

"What is good news is that the vaccines are still protecting us from hospitalization from delta. We don't know how long that will last and whether additional mutations will create a new version."