What are the recommended Canadian pneumococcal vaccination schedules for infants, children, adults (including those 19‑64 with chronic conditions or immunocompromise) and adults aged 65 years and older?

Canadian Pneumococcal Vaccine Guidelines

As of November 2024, Canada's National Advisory Committee on Immunization (NACI) recommends one dose of either PCV20 or PCV21 for all adults aged ≥65 years and for adults <65 years at increased risk of invasive pneumococcal disease (IPD), regardless of prior pneumococcal vaccination history 1.

Infants and Children

Routine Infant Schedule

• Standard schedule: PCV administered at 2,4, and 12 months (2+1 schedule) for low-risk infants 2
• This schedule has demonstrated 92% effectiveness against vaccine-serotype IPD after completion 2

High-Risk Children

For children with chronic conditions (sickle cell disease, asplenia, immunocompromising conditions):

• Complete age-appropriate PCV series first
• Add PPSV23 at age ≥2 years, administered >2 months after final PCV dose 3
• One lifetime booster of PPSV23 five years after the initial PPSV23 dose 3

Adults Aged 19-64 Years

Immunocompetent Adults with Chronic Conditions

For adults with diabetes, chronic heart/lung/liver disease, alcoholism, or smoking:

• One dose of PCV20 or PCV21 1
• Previously, PPSV23 was recommended, but newer guidelines prioritize higher-valency conjugate vaccines 4

Immunocompromised Adults and High-Risk Conditions

For adults with immunocompromising conditions, CSF leak, cochlear implant, asplenia, chronic renal failure, or HIV:

• One dose of PCV20 or PCV21, regardless of previous pneumococcal vaccination 1
• If previously received only PPSV23: Give PCV20/PCV21 ≥1 year after last PPSV23 dose
• Booster PPSV23: One lifetime booster five years after initial PPSV23 (for those who received PPSV23 before the updated guidelines) 3

Critical timing consideration: For patients starting immunosuppressive therapy, administer pneumococcal vaccines before initiating treatment when possible 5.

Adults Aged ≥65 Years

All Adults ≥65 Years

• One dose of PCV20 or PCV21, regardless of prior pneumococcal vaccination history 1
• This represents a significant simplification from previous complex sequential strategies

Previously Vaccinated Adults ≥65 Years

The 2024 Canadian guidelines eliminate the need for additional doses in most cases:

• If received PCV13 and/or PPSV23 previously: Still give one dose of PCV20 or PCV21 1
• Minimum interval: ≥5 years from last pneumococcal vaccine dose is prudent, though the guideline states "regardless of previous vaccination history"

High-Risk Adults ≥65 Years

For those with immunocompromising conditions:

• Same recommendation: One dose of PCV20 or PCV21 1
• Consider dual PCV20+PCV21 strategy for very high-risk individuals, though this is not yet formally recommended 6

Key Differences from U.S. Guidelines

Important caveat: The evidence provided includes primarily U.S. ACIP guidelines [@1-5@, @7-9@, 7], which differ substantially from current Canadian recommendations:

• U.S. approach: Complex sequential strategies with PCV13/PCV15 followed by PPSV23, with shared decision-making for PCV13 in healthy adults ≥65 8
• Canadian approach: Simplified single-dose PCV20 or PCV21 strategy for all eligible adults 1
• Rationale: Canada has adopted newer higher-valency conjugate vaccines (PCV20/PCV21) as the primary strategy, moving away from polysaccharide vaccines and complex sequential schedules 1

Practical Implementation

Vaccine Selection: PCV20 vs PCV21

• PCV21 is preferred where PCV7 serotypes are well-controlled (which applies to Canada given long-standing pediatric PCV programs) 6
• PCV20 provides excellent coverage of invasive and virulent serotypes 6
• Both are acceptable; choice may depend on local serotype epidemiology and availability 1

Common Pitfalls to Avoid

1. Don't delay vaccination waiting for "optimal" timing in previously vaccinated patients—the guideline states "regardless of previous vaccination history" 1
2. Don't use PPSV23 as primary strategy in newly eligible adults—conjugate vaccines are now preferred 1
3. Don't forget immunocompromised patients <65 years—they need vaccination regardless of age 1
4. Don't administer vaccines during active immunosuppression when avoidable—vaccinate before starting therapy 5

Documentation and Tracking

Given that 22% of vaccinations may be missed if relying solely on individual health records, verify vaccination history through provincial immunization registries 9. This is particularly important given the complexity of previous recommendations and the transition to new guidelines.

Serotype Coverage Considerations

The shift to PCV20/PCV21 addresses important gaps:

• PPSV23 additional serotypes account for 32-37% of IPD in adults ≥65 8
• PCV20 covers highly invasive and virulent serotypes, reducing risk of serotype replacement 6
• PCV21 adds eight serotypes not in previous vaccines but should only be used where PCV7 serotypes are controlled 5, 6