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10 Delta variant cases connected to outbreak at Calgary hospital were fully immunized


Alberta’s top doctor confirms 10 people connected to COVID-19 Delta variant outbreaks at Calgary’s Foothill Medical Centre were fully immunized before testing positive for the disease.

“What we're monitoring now is whether or not they had, as we would expect, a milder course of illness,” said Dr. Deena Hinshaw, Alberta’s chief medical officer of health, during Thursday’s provincial COVID-19 briefing.

According to Alberta Health Services, one dose of an mRNA vaccine — like Pfizer and Moderna— offers 73 per cent protection against the alpha variant. That immunity bumps up to 91 per cent with a second dose.

When it comes to the Delta variant strain, first identified in India, a first dose offers 33 per cent protection, and second dose 88 per cent.

“While we can see a few cases that have broken through the vaccine, the vast majority of people who are vaccinated will have protection,” said Hinshaw.

As of Friday, AHS confirms 16 cases of the B.1.617.2 variant in patients on two units at Foothills Medical Centre. Six healthcare workers have also tested positive for the variant.

Six of the patient cases and five health-care workers had received two doses of vaccine prior to becoming sick while seven patients and one health-care worker had just one dose.


AHS says while the spread of the variant is a concern at both hospitals, most of the infected individuals have only had mild symptoms of the disease.

"It’s important to remember that even after immunization, it’s still possible to contract COVID-19. However, if immunized with either one or two doses, people are less likely to experience severe illness or require hospitalization," said Kerry Williamson, executive director of communications with AHS.


"For example, in the case of these two outbreaks, only one of the 22 people have required ICU care. The majority of both patients and healthcare workers have experienced mild symptoms."

Williamson adds vaccines are 33 per cent effective against Delta variant after the first dose and 80 per cent effective following the second.

The hospital has experienced several outbreaks over the course of the pandemic, but this is the first involving the Delta variant.

The hospital remains open and has capacity to treat all patients, though AHS said the two units affected by the outbreaks are not accepting admissions. Patient transfers to long-term care centres from the two units with the Delta variant are also on hold. Top Stories

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