What is the recommended vaccination strategy using Prevnar 20 (Pneumococcal conjugate vaccine) and Prevnar 21 (Pneumococcal conjugate vaccine) for adults at high risk of pneumococcal disease?

Pneumococcal Vaccination Strategy for Adults at High Risk of Pneumococcal Disease

For adults at high risk of pneumococcal disease, the Advisory Committee on Immunization Practices (ACIP) recommends a single dose of either PCV21, PCV20, or PCV15 followed by PPSV23, with the specific choice depending on vaccination history and local serotype prevalence. 1

Risk Groups Requiring Pneumococcal Vaccination

Adults at high risk of pneumococcal disease include:

1. All adults aged ≥65 years
2. Adults aged 19-64 years with:
   • Immunocompromising conditions:
     • Chronic renal failure
     • Nephrotic syndrome
     • Immunodeficiency
     • Iatrogenic immunosuppression
     • Generalized malignancy
     • HIV infection
     • Hodgkin disease, leukemia, lymphoma, multiple myeloma
     • Solid organ transplant
     • Congenital or acquired asplenia
     • Sickle cell disease or other hemoglobinopathies
   • Chronic medical conditions:
     • Alcoholism
     • Chronic heart disease (including congestive heart failure and cardiomyopathies)
     • Chronic liver disease
     • Chronic lung disease (including COPD, emphysema, and asthma)
     • Cigarette smoking
     • Diabetes mellitus
   • Other high-risk conditions:
     • CSF leak
     • Cochlear implant

Vaccination Recommendations Based on Prior Vaccination Status

For Adults with No Prior Pneumococcal Vaccination or Unknown History:

1. Adults aged ≥65 years:

   • A single dose of PCV21, PCV20, or PCV15
   • If PCV15 is used, follow with PPSV23 ≥1 year later
   • For immunocompromised patients receiving PCV15, the minimum interval before PPSV23 can be shortened to 8 weeks 1

2. Adults aged 19-64 years with immunocompromising conditions, CSF leak, or cochlear implant:

   • A single dose of PCV21, PCV20, or PCV15
   • If PCV15 is used, follow with PPSV23 ≥8 weeks later 1

3. Adults aged 19-64 years with chronic medical conditions:

   • A single dose of PCV21, PCV20, or PCV15
   • If PCV15 is used, follow with PPSV23 ≥1 year later 1

For Adults with Prior PPSV23 Vaccination:

• Administer a single dose of PCV21, PCV20, or PCV15 ≥1 year after the last PPSV23 dose 1

For Adults with Prior PCV13 Vaccination:

• Administer a single dose of PCV21, PCV20, or PPSV23 ≥1 year after the PCV13 dose
• For immunocompromised patients receiving PPSV23, administer ≥8 weeks after PCV13 1

For Adults with Prior PCV13 and PPSV23 Vaccination:

• For adults aged ≥65 years who completed the recommended series with both PCV13 and PPSV23, shared clinical decision-making is recommended regarding administration of a single dose of PCV21 or PCV20
• If decided, administer ≥5 years after the last pneumococcal vaccine dose 1

Special Considerations

Serotype Coverage and Selection

• Important note: PCV21 does not contain serotype 4, which is included in PCV20, PCV15, and PPSV23
• In populations where ≥30% of pneumococcal disease is due to serotype 4 (such as parts of the western United States, Alaska, Navajo Nation), PCV20 or PCV15+PPSV23 is preferred over PCV21 1

Coadministration with Other Vaccines

• Pneumococcal vaccines can be administered with other age-appropriate vaccines at the same visit if there are no specific contraindications 1

Clinical Pearls and Pitfalls

1. Avoid missed opportunities: Assess vaccination status at every clinical encounter for high-risk adults.

2. Consider local epidemiology: In regions with high serotype 4 prevalence, PCV21 may provide less comprehensive coverage than PCV20 or PCV15+PPSV23.

3. Timing matters: Respect the minimum intervals between vaccines when using PCV15 followed by PPSV23:

   • 8 weeks for immunocompromised patients
   • 1 year for immunocompetent patients with chronic conditions

4. For patients who received PCV15 but haven't completed the series with PPSV23: A single dose of PCV21 or PCV20 may be used if PPSV23 is not available 1

5. Recent expansion of recommendations: As of October 2024, ACIP now recommends a single dose of PCV for all PCV-naïve adults aged ≥50 years, even without risk conditions 2

By following these recommendations, clinicians can optimize protection against pneumococcal disease for high-risk adults, reducing morbidity and mortality associated with invasive pneumococcal disease and pneumococcal pneumonia.