COVID-19 Booster Doses Have Been Officially Recommended For Some Canadians By NACI
NACI advises a three-dose series but only for a specific group of eligible Canadians.
Canada's vaccine advisory board has officially laid out directions for who should be receiving COVID-19 booster doses.
According to a release from the National Advisory Committee on Immunization (NACI) on Friday, September 10, Canadians in authorized age groups who are "moderately to severely immunocompromised" should receive a three-dose series of an authorized mRNA vaccine.*
2/3 Moderately or severely immunocompromised people, including those receiving immunosuppressive therapies, are more likely to have a lower initial immune response to only 2 doses of #COVID19Vaccines and therefore should get an additional dose.— Dr. Theresa Tam (@Dr. Theresa Tam) 1631287407
"Recent studies show that some individuals who are moderately to severely immunocompromised who did not respond to or who had a reduced immune response after two doses of an mRNA vaccine can have an increased immune response after a third dose of an mRNA vaccine," a summary of NACI's latest research said.
Technically, NACI said, the three-dose series does not include a booster dose since it is not about improving an immune response over time; instead, the advisory board says immunocompromised individuals need three doses to compensate for an already weakened immune system.
If eligible immunocompromised Canadians have not yet been vaccinated, NACI advised that they receive a three-dose series. If eligible immunocompromised Canadians have been fully vaccinated, NACI recommends an extra dose of an approved mRNA vaccine, no matter what type of vaccine they first received.
The time between a second and third dose of a COVID-19 vaccine should be 28 days, NACI said. They also included information on who falls under the category of "moderately to severely immunocompromised."
"Booster doses may eventually be needed for specific populations and/or the general population if protection from a 1- or 2-dose primary vaccine series shows signs of waning," NACI also wrote in its updated guidance. "Studies on how long protection from a 1- or 2-dose series lasts in the general population and on the potential need for booster doses are ongoing."
Health Canada has a robust website with all the latest information on COVID-19 vaccines and can answer any questions you may have.
*This article has been updated.