Worker immunizations at Site C have been put on hold after the province suspended use of the AstraZeneca COVID-19 vaccine for those younger than 55.
The province sent 15,000 doses of the AstraZeneca vaccine to industrial sites across northern B.C. this month as part of a priority effort to immunize workers at Site C, LNG Canada, Rio Tinto Alcan, and the Coastal GasLink and Trans Mountain pipelines.
But the province suspended use of the vaccine for younger people on Monday following growing concerns the vaccine is tied to a small number of rare blood clots.
“There has been less than 30 cases identified around the world, primarily in Europe, but it is a serious condition and could lead to serious outcomes,” provincial health officer Dr. Bonnie Henry said during a briefing.
“If you have received the AstraZeneca vaccine and it’s more than 20 days since you’ve received it, there is no concern.”
BC Hydro says about 1,400 Site C workers have already received the vaccine on site.
"We're following guidance from the health authorities and have paused the use of the vaccine at our onsite clinic," spokesman Dave Conway said Tuesday. "We're awaiting further direction from health authorities about next steps."
BC Hydro has reported 60 cases among the Site C workforce to date, including five active cases as of Tuesday. There are 1,257 workers at the work camp, including 14 in self-isolation.
Dr. Henry said those who have already received the vaccine should monitor for symptoms such as headaches or swelling.
“We will know much more of this in the coming days,” she said.
Risk of blood clots
Prince Edward Island also suspended the use of the vaccine for certain age groups Monday morning, followed by Quebec and Manitoba.
Shortly before Henry’s announcement, the National Advisory Committee on Immunization updated its guidelines with the recommendation that the country suspend use of the vaccine for anyone under the age of 55.
Dr. Shelley Deeks, the vice-chair of Canada's National Advisory Committee on Immunization, said the committee updated its recommendations amid new data from Europe that suggests the risk of blood clots is now potentially up to one in 100,000 — much higher than the one in one million risk believed before.
Health Canada demanded Monday that AstraZeneca do a detailed study on the risks and benefits of its COVID-19 vaccine across multiple age groups, and Deeks said the advisory committee recommended the shot be suspended for younger groups pending the outcome of that review.
Deeks said most of the patients in Europe who developed a rare blood clot after vaccination with AstraZeneca were women under the age of 55, and the fatality rate among those who developed clots is as high as 40%.
The blood clot condition is known as Vaccine-Induced Prothrombotic Immune Thrombocytopenia. Deeks said it is treatable, and the fatality rate could go down now that it has been identified and symptoms are communicated.
The B.C. government’s immunization plan sought to immunize 320,000 essential workers outside of their age group using the AstraZeneca vaccine.
Henry said more details about how the suspension of the AstraZeneca vaccine will affect vaccination plans for essential workers will be revealed in the coming days.
“It is possible that we may need to use the vaccine in people where we know this rare event is not likely to happen,” she said, referencing those over 55 years old.
— with files from The Canadian Press
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