The National Advisory Committee on Immunization is urging long-term care homes to give boosters to residents immediately, as the Delta variant breaks out in facilities across the country.
The new guidance was released Tuesday after the committee reviewed evidence about waning immunity from the vaccines, the latest safety data and the spread of COVID-19 across the country.
The committee recommends long-term care residents and people living in seniors' homes receive another shot of an mRNA COVID-19 vaccine — like Pfizer-BioNTech or Moderna — as long as it has been six months since their last shot.
A booster dose of a viral vector vaccine like Oxford-AstraZeneca is only recommended when Pfizer or Moderna vaccines are unavailable or the person can't have an mRNA vaccine for medical reasons.
"At this time, boosters are not necessary for most of the population, but we want to be sure to address early signs of waning among seniors residing in these settings where shared and close living spaces increase the risk of exposure," chief public health officer Dr. Theresa Tam wrote in a statement.
NACI says there are signs that vaccine protection might not last as long for seniors in congregate settings like long-term care as it does for other populations in Canada.
Canadian studies have suggested that even though people in long-term care had a good initial antibody response to two doses of vaccine, the majority of residents did not have a detectable level of antibodies against the Delta variant six months later.
"While the vaccines initially worked very well to protect this group, we are starting to see signs of outbreaks again in long-term care settings and we are looking to prevent the level of severe outcomes this population experienced early in the pandemic," NACI chair Dr. Shelley Deeks wrote in a statement.
Right now, 260 long-term care and retirement homes are battling active outbreaks of COVID-19 in Canada, according to a tracker developed by the National Institute on Aging.
That's up from just 201 long-term care outbreaks last week.
Half of those outbreaks are happening in Alberta, which is dealing with a spiralling health crisis during the latest wave of the pandemic.
Long-term care has borne the brunt of the COVID-19 pandemic in Canada, where aging residents and congregate living proved to be a tragic combination.
About 69 per cent of Canada's total pandemic-related deaths happened in long-term care homes as of February 2021, according to the Canadian Institute for Health Information.
The new advice comes weeks after provinces like Ontario announced they would extend third-dose eligibility to long-term care residents.
Saskatchewan, Alberta, and most recently, Quebec are also offering boosters to residents in care homes, while Manitoba has extended third doses to long-term care residents in First Nations.
NACI has previously recommended boosters for people who are moderately to severely immunocompromised, as evidence shows some immunocompromised people have a lower immune response to COVID-19 vaccines compared to others.
This report by The Canadian Press was first published Sept. 28, 2021.
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