What is the recommended series of pneumococcal conjugate vaccine (PCV) immunization for an adult patient who has previously received PCV13 (Pneumococcal Conjugate Vaccine 13-valent)?

Pneumococcal Vaccination Series After Prior PCV13

For adults who have previously received PCV13 only, complete the series with a single dose of either PCV20 or PPSV23, administered at least 1 year after the PCV13 dose (or ≥8 weeks for immunocompromised patients). 1

Standard Approach for Immunocompetent Adults

The preferred completion strategy is a single dose of PCV20 given ≥1 year after PCV13, which provides broader serotype coverage and completes the series without requiring additional vaccines. 1, 2

• PCV20 covers 7 additional serotypes beyond PCV13 and offers superior immunologic memory through T-cell dependent responses compared to polysaccharide vaccines 2, 3
• If PCV20 is used, the pneumococcal vaccination series is complete—no additional PPSV23 is needed 3
• Alternatively, PPSV23 can be given ≥1 year after PCV13 to complete the series, though this provides less durable immune response 1, 2

Accelerated Schedule for High-Risk Patients

For adults with immunocompromising conditions (chronic renal failure, HIV, malignancy, transplant, asplenia, sickle cell disease), CSF leak, or cochlear implant, the minimum interval between PCV13 and the completion vaccine is reduced to ≥8 weeks. 1

• These high-risk patients can receive either PCV20 ≥8 weeks after PCV13 (completing the series), or PPSV23 ≥8 weeks after PCV13 1
• If PPSV23 is chosen instead of PCV20, a second PPSV23 dose is recommended ≥5 years later for immunocompromised patients 1
• The shorter 8-week interval reflects the urgent need for protection in patients at higher risk for invasive pneumococcal disease 4

Age-Specific Considerations

Review pneumococcal vaccination status again when the patient turns 65 years old, as additional doses may be indicated based on prior vaccination history and timing. 1, 4

• Adults aged 19-64 years who complete their series should have their vaccination status reassessed at age 65 4
• If PCV13 was given before age 65, completion with PCV20 or PPSV23 at age ≥65 is recommended if not already done 2, 4

Clinical Evidence Supporting These Recommendations

The 2023 ACIP guidelines are based on Phase III clinical trials demonstrating that PCV20 administered ≥6 months after PCV13 was safe and immunogenic in adults ≥65 years 1, 5. While no direct data exist for PCV20 use in immunocompromised adults who previously received PCV13, repeat PCV13 doses have shown modest immunogenicity in this population 1. The immunologic advantages of conjugate vaccines (memory B-cell formation, T-cell dependent responses) over polysaccharide vaccines support PCV20 as the preferred option 2, 3.

Common Pitfalls to Avoid

• Do not give PPSV23 after PCV20—if PCV20 is used to complete the series, no additional pneumococcal vaccines are needed 3
• Do not co-administer pneumococcal vaccines on the same day—they must be given sequentially with appropriate intervals 4
• Do not delay vaccination waiting for complete medical records—use verbal history and proceed with indicated vaccination 4
• For immunocompromised patients requiring elective splenectomy or immunosuppressive therapy, complete vaccination ≥2 weeks before the procedure 4