Who is eligible for a third dose of the COVID-19 vaccine to complete the primary series?
Certain populations are at increased risk of severe outcomes from COVID-19 and have demonstrated a lower immune response to a complete two-dose COVID-19 vaccine series due to their underlying condition. The Government of Ontario recommends that a third dose of a mRNA COVID-19 vaccine be offered as a primary series to those who are moderately to severely immunocompromised. A third dose will help provide an improved immune response for these high-risk individuals and will add an extra layer of protection.
Moderately to severely immunocompromised individuals (18 years of age and older) who are eligible for a three-dose primary series are also recommended to receive a booster dose (4th dose) 3 months (84 days) after completion of the primary series. Moderately to severely immunocompromised individuals (12 to 17 years of age) who are eligible for a three-dose primary series are recommended to receive a booster dose (4th dose) 6 months (168 days) after completion of the primary series. Booster doses (4th dose) are not recommended for moderately to severely immunocompromised individuals under the age of 12.
Check out our COVID-19 vaccine clinic page for current information on eligibility, clinic dates, and booking instructions.