Why is only one dose of Prevnar 20 (Pneumococcal conjugate vaccine) required?

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Last updated: April 2, 2025View editorial policy

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From the Guidelines

You only need 1 dose of Prevenar 20 because it provides sufficient immune protection against pneumococcal disease with a single administration, as recommended by the Advisory Committee on Immunization Practices in 2023 1.

Key Points

  • The single dose of Prevenar 20 is recommended for adults aged 19-64 years with a chronic medical condition, as outlined in the 2023 guidelines 1.
  • This vaccine contains 20 serotypes of Streptococcus pneumoniae bacteria, providing broad protection against pneumococcal disease.
  • The conjugation technology in Prevenar 20 enhances the immune response, creating a stronger and more durable protection compared to older pneumococcal vaccines.

Recommendations

  • For adults who have not previously received a pneumococcal vaccine, a single dose of Prevenar 20 is recommended 1.
  • For adults who have previously received PPSV23, a single dose of Prevenar 20 is recommended after a ≥1 year interval since the last PPSV23 dose 1.
  • Certain immunocompromised individuals might have different recommendations, so it's essential to consult with a healthcare provider about specific situations.

Benefits

  • The single-dose regimen improves compliance and reduces the burden on patients who might otherwise need to return for additional doses.
  • Prevenar 20 provides long-lasting protection against the included pneumococcal serotypes, reducing the risk of pneumococcal disease and its complications.

From the FDA Drug Label

2.6 Vaccination Schedule for Individuals 18 Years of Age and Older Prevnar 20 is administered as a single dose.

The single dose of Prevnar 20 for individuals 18 years of age and older is likely due to the immune responses generated by the vaccine, as measured by opsonophagocytic activity (OPA) assay, which is considered sufficient for this age group 2.

  • Key points:
    • Single dose: Prevnar 20 is administered as a single dose for individuals 18 years of age and older.
    • Immune responses: The vaccine's immune responses, as measured by OPA assay, support the use of a single dose in this age group.

From the Research

Immunogenicity of Prevnar 20

  • The 20-valent pneumococcal conjugate vaccine (PCV20; Prevnar20) has been shown to induce robust immune responses to all 20 S. pneumoniae serotypes covered by the vaccine when administered as a single dose by intramuscular injection 3.
  • A phase 2 study demonstrated that PCV20 elicited functional immune responses as measured by opsonophagocytic activity (OPA) titers, with geometric mean fold rises from baseline ranging from 6.0 to 113.4 for all 20 serotypes included in the vaccine 4.

Single Dose Efficacy

  • The immunogenicity of PCV20 in adults has been demonstrated in a well-designed program of clinical trials, which showed that a single dose of PCV20 induced robust immune responses to all 20 S. pneumoniae serotypes covered by the vaccine 3.
  • PCV20 was well tolerated, with a tolerability and safety profile similar to that for PCV13, and no serious vaccine-related adverse events were reported 4.

Comparison to Other Vaccines

  • PCV20 contains all components of PCV13 with the addition of polysaccharide conjugates of seven more serotypes, selected based on their generalized geographic distribution and relative prevalence as a cause of pneumococcal disease 3.
  • The glycoconjugate PCV13 vaccine induces an antigenically broader, more durable, polyfunctional antibody response compared to the polysaccharide vaccine PPSV23 5.

Mechanism of Action

  • Pneumococcal conjugate vaccines, such as PCV20, have the bacterial polysaccharides covalently conjugated to an immunogenic carrier protein, resulting in the formation of memory B lymphocytes and long-acting immunologic memory 6.
  • This mechanism of action allows for a single dose of PCV20 to provide protection against pneumococcal disease, as the immune system is able to remember the vaccine antigens and respond quickly to future infections.

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Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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