Prevnar 20: A 20-Valent Pneumococcal Conjugate Vaccine
Prevnar 20 (PCV20) is a 20-valent pneumococcal conjugate vaccine that prevents invasive pneumococcal disease and pneumonia caused by 20 serotypes of Streptococcus pneumoniae in adults and children as young as 6 weeks of age. 1
Composition and Mechanism
Prevnar 20 is a sterile suspension containing:
- Capsular saccharide antigens from 20 S. pneumoniae serotypes (1,3,4,5, 6A, 6B, 7F, 8, 9V, 10A, 11A, 12F, 14, 15B, 18C, 19A, 19F, 22F, 23F, and 33F)
- Each serotype is individually conjugated to a non-toxic diphtheria CRM197 protein
- Each 0.5 mL dose contains approximately 2.2 μg of each serotype (except 4.4 μg of 6B)
- 51 μg CRM197 carrier protein and aluminum phosphate adjuvant 1
The conjugation of polysaccharides to proteins transforms the immune response from T-independent to T-dependent, which:
- Stimulates T-helper cell response
- Creates a substantial primary response in infants
- Generates a strong booster response upon reexposure 2
Indications
Prevnar 20 is FDA-approved for:
- Prevention of invasive disease caused by all 20 S. pneumoniae serotypes in individuals ≥6 weeks of age
- Prevention of otitis media caused by serotypes 4, 6B, 9V, 14, 18C, 19F, and 23F in children 6 weeks through 5 years of age
- Prevention of pneumonia caused by all 20 serotypes in individuals ≥18 years of age 1, 3
Evolution from Earlier Vaccines
Prevnar 20 represents an evolution in pneumococcal vaccination:
- Original Prevnar (PCV7) contained 7 serotypes (4, 6B, 9V, 14, 18C, 19F, and 23F)
- Prevnar 13 (PCV13) added 6 more serotypes (1,3,5, 6A, 7F, and 19A)
- Prevnar 20 (PCV20) adds 7 additional serotypes (8, 10A, 11A, 12F, 15B, 22F, and 33F) 4
This expanded coverage targets serotypes responsible for significant disease burden not covered by previous vaccines. The additional serotypes were selected based on their geographic distribution and prevalence as causes of pneumococcal disease 4.
Effectiveness
Prevnar 20 induces:
- IgG antibodies against all 20 vaccine serotypes
- Opsonophagocytic activity (OPA) that facilitates killing of S. pneumoniae 1
Clinical studies have demonstrated:
- Robust immune responses to all 20 serotypes after a single dose in adults
- Comparable safety profile to PCV13 5, 4
Vaccination Recommendations
According to the Advisory Committee on Immunization Practices (ACIP):
- For adults aged ≥65 years: a single dose of PCV20 is recommended
- For adults aged 19-64 years with immunocompromising conditions, CSF leaks, or cochlear implants: a single dose of PCV20
- For adults aged 19-64 years with chronic medical conditions: a single dose of PCV20 2, 6
For adults who previously received PPSV23, the ACIP recommends administering PCV20 ≥1 year after the last PPSV23 dose. If PCV20 is used in place of any dose of PPSV23, the vaccination series is considered complete 6.
Clinical Significance
The development of Prevnar 20 addresses important clinical needs:
- Expands coverage against pneumococcal serotypes causing significant disease
- Provides a simpler, single-dose regimen for most adults
- Offers protection against serotypes increasingly associated with antibiotic resistance 5, 7
Important Considerations
- Prevnar 20 can be administered with other age-appropriate vaccines at the same visit
- Assessment of vaccination status should occur at every clinical encounter to avoid missed opportunities
- For patients who have received PCV13 previously, a single dose of PCV20 can be administered ≥1 year after the PCV13 dose (≥8 weeks for immunocompromised patients) 6
Prevnar 20 represents a significant advancement in pneumococcal disease prevention by expanding serotype coverage while maintaining the benefits of conjugate vaccine technology.