The following are the minimum intervals required between doses; however, the above dose intervals are recommended.

Minimum interval between first and second dose:

Minimum interval between second and third dose: 3 months

Minimum interval between third and fourth dose: 3 months (84 days)

Minimum interval between first and second booster dose: 3 months (84 days)

Please Note: if you are immunocompromised, different dose intervals apply. See below.

• Individuals receiving dialysis (hemodialysis or peritoneal dialysis)
• Individuals receiving active treatment (e.g., chemotherapy, targeted therapies, immunotherapy) for solid tumour or hematologic malignancies
• Recipients of solid-organ transplant and taking immunosuppressive therapy
• Recipients of chimeric antigen receptor (CAR)-T-cell therapy or hematopoietic stem cell transplant (within 2 years of transplantation or taking immunosuppression therapy)
• Individuals with moderate to severe primary immunodeficiency (e.g., DiGeorge syndrome, Wiskott-Aldrich syndrome)
• Individuals with HIV with prior AIDS defining illness or prior CD4 count ≤200/mm3 or prior CD4 fraction ≤ 15% or (in children 5-11 years) perinatally acquired HIV infection
• Individuals receiving active treatment with the following categories of immunosuppressive therapies: anti-B cell therapies (monoclonal antibodies targeting CD19, CD20 and CD22), high-dose systemic corticosteroids (refer to the Canadian Immunization Guide [6] for suggested definition of high dose steroids), alkylating agents, antimetabolites, or tumor-necrosis factor (TNF) inhibitors and other biologic agents that are significantly immunosuppressive.

Those uncertain about their eligibility should contact their health care provider prior to receiving a vaccine. Prior to being vaccinated, individuals in these groups should consult with their treating provider to determine the exact timing of their vaccination.

The following are the minimum intervals required between doses; however, the above dose intervals are recommended.

Minimum interval between first and second dose:

Minimum interval between second and third dose: 28 days

Minimum interval between third and fourth (first booster) dose: 3 months (84 days)

Minimum interval between first and second booster dose: 3 months (84 days)

Recommended:

One additional dose of a HC authorized vaccine 28 days after your previous dose.

• A booster dose is recommended 6 months later (if aged 12 to 17) or 3 months later (if aged 18 or older).

Recommended:

A booster dose of a HC authorized vaccine 3 months after your second dose (if aged 18 or older) or 6 months after your second dose (if aged 12 to 17).

Recommended:

A fourth (booster) dose of a HC authorized vaccine 6 months after your third dose (if aged 12 to 17) or 3 months after your third dose (if aged 18 or older).