As Alberta continues its push to have people in the province vaccinated against COVID-19, Dr. Deena Hinshaw shared some statistics Thursday that the chief medical officer of health said show the effectiveness of the vaccines.
Since Jan. 1, 96 per cent of Alberta’s confirmed COVID-19 cases were in individuals who were either unvaccinated or still within the two-week window after receiving their first dose, where their immunity hadn’t built up.
In the same time frame, Hinshaw said only 0.2 per cent of people contracted COVID-19 after that two-week window.
“This shows you the power of the vaccine at preventing infection.”
She added that 93 per cent of Alberta COVID-19 cases that required hospitalization were also either people who weren’t vaccinated or who were diagnosed within two weeks of their first dose.
Between Jan. 1 and Wednesday, there were 706 deaths due to COVID-19 in Alberta. Hinshaw said 88 per cent of those were unvaccinated, or had been diagnosed within that two-week period.
“These numbers reinforce just how important vaccines are,” Hinshaw said. “While no vaccine or treatment for any condition is ever perfect, these vaccines work better than we could have expected.”
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As of Thursday’s update, Alberta had administered 2,888,005 doses of COVID-19 vaccine. On Wednesday alone, the province gave more than 44,000 shots.
“We can expect both the number of hospitalizations and deaths due to COVID-19 to decrease even more as more of the population is protected by first and second doses,” Hinshaw said.
Alberta data also shows the Pfizer and Moderna vaccines are effective against the B.1.1.7 variant – also known as the variant first identified in the United Kingdom.
One shot of these vaccines gives a person about 73 per cent protection against that variant. After two doses, its effectiveness goes up to 91 per cent.
Against the P.1 variant – the variant first identified Brazil – these mRNA vaccines are about 75 per cent effective after one dose and 89 per cent effective after two doses.
Hinshaw said there wasn’t enough data to say how effective the AstraZeneca vaccine is against these variants, but that information will be released as it’s received.
Thursday COVID-19 numbers
On Thursday, the province confirmed an additional 296 cases over the previous 24 hours. The province conducted 6,808 tests, putting the positivity rate at about 4.6 per cent.
An additional 305 cases of variants were also confirmed over the last 24 hours.
Alberta currently has 411 people in hospital with COVID-19, with 120 of those people in the ICU.
Five additional deaths were reported to Alberta Health over the last 24 hours.
Four of the deaths included known comorbidities: a man in his 80s, a woman in her 50s and a man in his 70s in the Edmonton zone and a man in his 80s in the Calgary zone have died.
A woman in her 70s with no known comorbidities has also died in the Edmonton zone.
“We must never forget that these are not just numbers,” Hinshaw said. “They are people who lost their lives to COVID-19 and who leave behind family and friends who are grieving them.”
There are active alerts or outbreaks in 364 schools.
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Changes to variant contact tracing
Now that Alberta is again screening all positive COVID-19 cases for variants, case investigation teams will start second calls for cases involving the P.1 variant and B.1.617 –the variant first identified in India — again.
“The second notification will allow AHS to do even more in-depth investigations to find out where the case may have been exposed,” Hinshaw said.
The province stopped the practice May 1 as labs didn’t have the capacity to keep up as the number of daily cases started topping 2,000 per day.
Hinshaw said the province wants to pay particular attention to the low-volume variants of concern.
“In these cases we have opportunities for more aggressive containment.”
Second calls will not take place for cases of the B.1.17 variant as it is already the dominant strain in the province, Hinshaw said.