If you’re 50 or older, Canada’s National Advisory Committee on Immunization “strongly” recommends you get a COVID-19 vaccine booster shot.
The committee is also recommending that booster shots of an mRNA vaccine be offered to adults ages 18 to 49 at least six months after their second dose.
NACI made the recommendations Friday after the Canadian government requested the advisory group quickly provide the latest directives on booster use as the Omicron variant spreads across the world.
While the COVID-19 vaccines authorized by Health Canada have proven effective against infection, severe disease, hospitalization and death, Canada’s top doctor said the latest data suggests protection against infection decreases over time, and protection against severe illness may also decrease for older adults.
“Our primary focus is still to strongly recommend for the (older) groups, not only because they were at high risk potentially for serious outcomes, but because they were immunized earlier,” Dr. Theresa Tam said.
“Both the duration and whether they are at higher risk of serious outcomes are taken into account.”
As part of NACI’s updated guidance, boosters are strongly recommended for adults living in long-term care homes or other congregate living settings; those fully vaccinated with AstraZeneca or Johnson and Johnson; adults in or from First Nations, Inuit and Métis communities; and all front-line health-care workers having direct in-person contact with patients.
In addition, NACI suggests Pfizer’s booster be given to those 18 to 29 years old due to the lower risk of myocarditis/pericarditis in that vaccine. However, anyone 30 and up can get either Moderna or Pfizer.
Health Canada has approved Pfizer’s booster to be offered as a full dose, and Moderna’s booster to be offered as a half dose. Meanwhile, for vulnerable populations like the immunocompromised, NACI suggests a full dose of Moderna could be given as a booster.
“Offering booster doses will help ensure that protection against severe disease remains high, and may have an impact on spread in the community as well,” Dr. Shelley Deeks, chair of NACI, said in a written statement.
“It is important to note that there is no information yet on the impact of the new variant, Omicron, on the effectiveness of the vaccine.”
Deeks added that NACI will continue to monitor and provide updated advice as more is learned about Omicron.
Booster rollouts in provinces
So far, third shots have been administered mostly among vulnerable populations in parts of Canada. The discovery of Omicron last week has added increasing pressure to provinces doling out their own strategies.
As it stands, eligibility for boosters varies province by province. In most cases, provinces advise that boosters should be given at least six months after the second dose.
In Ontario, the province announced Thursday that it’s lowering the age of eligibility for COVID-19 booster shots to people aged 50 and older. They will be able to get their shots starting Dec. 13.
British Columbia is administering booster jabs to its elderly and most at-risk through to the December holiday, and will then expand to include all adults 18 and older in January.
NACI’s previous guidance on booster use recommended mRNA shots, like Pfizer or Moderna, be offered to people who are immunocompromised, those who live in long-term care centres and people over the age of 80.
At the time, the organization said it made its decision based on evidence showing that immunity provided by the vaccine could wane over time.
The discovery of Omicron, however, and the unanswered questions around its behaviour, prompted many countries to impose measures to protect themselves.
Canada has seen several Omicron infections since the variant was discovered in South Africa last week.
The federal government has imposed travel bans on several African nations, even though the mutation has spread beyond the continent.
The World Health Organization has classified Omicron as a variant of concern and said it poses a “very high” risk to the world’s pandemic fight.
The variant, which has multiple mutations, is not yet known to be more deadly or more transmissible than its counterparts. It’s also not clear if it makes current vaccines less effective.
Scientists are continuing to study the variant, and the WHO said Wednesday the world will know more about Omicron “within days.”
— with files from The Canadian Press