One week after Alberta lifted nearly all of its COVID-19 restrictions, many people are keeping a close eye on the most contagious Delta variant — while their number remains low, smoke is still rising in the province.
Alberta identified 21 other variant cases, including 10 of the Delta strain, in its daily update Wednesday.
The Calgary area has had the highest number of cases so far, with 694 of the 831 cases reported with 1,617 so far in the county.
Dr. Stephanie Smith, an infectious disease specialist at University of Alberta Hospital, said there are plenty of encouraging signs in the province — including a significant drop in overall COVID-19 cases and a decrease in pressure on hospitals.
“But I think we’re not quite out of the woods yet,” Smith said.
Sixty percent of active COVID-19 cases in Alberta are variants of concern and many are delta strains.
“The ratio is going up in relation to the delta,” she said. “About half of the changed cases now are delta copy.”
Smith said Delta is on track to become the dominant strain and she is concerned about large gatherings, including the Calgary Stampede, which has announced a number of precautions against the coronavirus.
“Is there a possibility of some sort of super-distributor event in those situations given that we still have some deltas in the community? I think the answer is yes.”
More than 43 percent of Albertans are fully immunized, leaving large segments of the population unprotected.
Until a higher proportion of eligible Albertans get two doses of the COVID-19 vaccine, there is still a risk to clusters, particularly in Calgary, where 84 percent of Delta cases are concentrated, Smith said.
Throwing “gasoline on that fire”
At the University of British Columbia, zoology professor and mathematical modeling expert Sally Otto has been tracking the delta variable.
She said the decline in case numbers in Alberta is mostly due to the decline in the ancient wild type of coronavirus and the old variants of concern (alpha and gamma).
“All of those are going downhill and downhill very steeply,” she said.
However, Delta is a different story.
“Delta numbers are low, but they’re not going down.”
Otto said reopening Alberta on July 1 gave the most transmissible variant a window.
So it’s as if a fire is already burning but the fire – it’s not burning, it’s not spreading. But then you throw gasoline on that fire.Sally Otto is a Mathematical Modeling Expert at the University of British Columbia
“You had something that was growing…very, very slowly, and then you opened it up. So it’s like there’s already a fire going on but the fire – it’s not raging, it’s not spreading. But then you throw gasoline on that fire. So we expect it to start. Delta is spreading faster and faster.”
Otto tied the daily growth rate (R-value) to about 0.004.
“That’s small but it’s positive. And…it means there’s no barrier. We don’t have room to open up before we start seeing delta growth because it’s already growing. So the only way to reduce that is to get more vaccinations and more vaccinations” .
Otto said Delta’s growth will be slow, as Albertans resume their normal activities at different rates. She expects it will take at least a month for the rise in this variable to be noticeable.
That would buy Alberta time to boost vaccination rates or, if necessary, re-impose restrictions in the worst-affected areas, she said.
“We will probably be fine for most of July and August, but the more we relax our behavior, the faster and faster this spike in cases will be,” she warned.
“I’m concerned about those people in Alberta who haven’t been vaccinated and I hope this is a call to encourage everyone to get vaccinated.”