An additional dose of the messenger RNA COVID-19 vaccine is recommended for:
- People on dialysis
- Certain people with a weakened immune system, including those:
- receiving chemotherapy or radiotherapy
- taking medication that affects their immune system
- living with HIV who have a CD4 cell count lower than 500 / mm3 or who are not on treatment
- Residents of residential and long-term care centres (CHSLD) and intermediate and family-type resources (RI-RTF)
- People living in private seniors’ residences (RPA)
An additional dose is recommended for these individuals based on available immune response data and developments in the epidemiological situation. Studies show that these people have a higher risk of complications associated with COVID-19. They might also have less protection after two doses.
Administering an additional dose, ideally of a messenger RNA vaccine, provides better protection against COVID-19 where there is widespread circulation of the Delta variant.
It is important that these people maintain the basic health instructions because they might have less protection than the rest of the population.
The additional dose must be given four weeks or more after the second dose. For CHSLDs, RPAs, and RI-RTFs, the recommended interval is six months. However, a minimum period of five months will be authorized so that users and residents can be vaccinated against influenza and COVID-19 at the same time, as part of seasonal influenza vaccination operations.
The additional dose is necessary even if the person has already had COVID-19.
How to get vaccinated
Last update: September 28, 2021