EDMONTON -- Canadians living in long-term care homes and other congregate-care settings, such as retirement homes or assisted-living facilities, should receive a COVID-19 vaccine booster shot, Canada's vaccine advisory body recommended on Tuesday.
The updated guidance comes more than two weeks after the advisory panel recommended that moderately to severely immunocompromised Canadians should receive three doses of an authorized mRNA vaccine, such as Pfizer-BioNTech or Moderna.
In a release issued Tuesday, the panel says offering a booster dose to long-term care residents will help to enhance protection and prevent outbreaks as the Delta variant fuels a fourth wave of COVID-19 in Canada.
The National Advisory Committee on Immunization (NACI) does not dictate policy, but their recommendations have served as a key guide for policymakers throughout the pandemic.
NACI specified that they recommend long-term care residents be offered a third dose of an mRNA COVID-19 vaccine at least six months after their second dose. They added that a booster shot of an authorized viral vector vaccine should be considered only when other vaccines are “contraindicated or inaccessible.”
“Canadians residing in long-term care (LTC) homes and seniors living in other congregate settings, such as retirement homes or assisted-living facilities, are at increased risk for COVID-19 infection because of their daily interactions with other residents and staff,” the NACI statement reads.
“Offering a booster dose of COVID-19 vaccine to LTC residents and seniors living in other congregate settings is a strategy to enhance protection and prevent outbreaks among this vulnerable population.”
The statement pointed out that while those who live in long-term care make up only 1.1 per cent of the Canadian population, long-term care residents “accounted for approximately two thirds of all reported deaths associated with COVID-19 during the first and second waves of the pandemic, and half of all reported deaths to date.”
The cumulative case fatality rate of the virus among long-term care residents in Canada is estimated at 27 per cent, NACI stated.
NACI explained that there are several reasons behind the change in recommendation.
One is the growing evidence that the immunity provided by the vaccines may wane slightly over time.
NACI stated that studies they have reviewed demonstrated a waning immunity in long-term care residents. They note that it’s difficult to measure exactly how much immunity a person has against the virus at any given time, but that the presence of antibodies has been correlated with protection against infection.
“Emerging data from an ongoing longitudinal serology study in LTC residents and staff in Ontario found the majority of LTC residents failed to demonstrate a detectable neutralization [antibody level] against the B.1.617.2 (Delta) strain at six months after completing the vaccine series,” the statement reads.
NACI pointed out that since long-term care residents were among the very first in Canada to receive vaccines — a move which demonstrated the significant effectiveness of the vaccines by sharply cutting down on deaths in long-term care last winter and spring — if the protection does wane, long-term care residents would see that effect earlier than others.
They also largely received their doses with the manufacturer’s recommended gap between the first and the second. NACI stated that some studies have shown that for the general population, longer intervals between the two doses have been correlated with a higher immune response.
One of the biggest reasons for the change in recommendation is the rise in cases during this Delta-variant-fuelled fourth wave.
The Delta variant is significantly more transmissible than both the original strain and the Alpha variant.
Although the COVID-19 vaccines have been proven to be very effective at preventing hospitalization and deaths, there are still rare breakthrough cases of COVID-19, and individuals infected with Delta may be more infectious to others.
There has been a rise in outbreaks in long-term care facilities during this fourth wave as cases find their way into these homes, sometimes through unvaccinated staff.
Quoc Dinh Nguyen, a geriatrician and adjunct clinical professor at the University of Montreal, told CTVNews.ca last week that those in long-term care are at a higher risk than other vaccinated individuals.
“If you compare people who have two doses that are young, and two people have two doses that are older, and especially those in nursing homes, they will still be the one at highest risk of death and hospitalization,” he said.
Several provinces were already offering booster shots to long-term care residents this fall ahead of the new recommendation, including Ontario, Alberta and Saskatchewan.
Whether other provinces will follow suit now that NACI has officially recommended the policy remains to be seen.
NACI also clarified that this new recommendation is for those in long-term care who mounted an “adequate response” to their initial two doses to receive a third dose to “restore protection that may have waned.” The organization says this is different from earlier recommendations for certain immunocompromised groups to receive a third dose because they had not achieved an adequate immune response from two doses.
Wealthy countries doling out third doses to citizens has been controversial. The World Health Organization has stated that there should be more first doses provided to countries that lack vaccine access before highly-vaccinated countries — such as Canada — provide third doses.
