Last reviewed 2026-04-20 · How we verify

Prevnar 20 (pneumococcal 20-valent conjugate vaccine (PCV20))

20-valent pneumococcal conjugate vaccine that elicits immune responses against 20 Streptococcus pneumoniae serotypes

Prevnar 20, developed by Pfizer Inc., stands as the world's best-selling drug with annual revenues of $6.4 billion, dominating the market for pneumococcal vaccines. Its competitive edge lies in its 20-valent formulation, which provides robust immune responses against 20 serotypes, including unique serotypes not covered by Merck’s Vaxneuvance or Pneumovax 23. A key risk is the requirement for a PD-L1 companion diagnostic for several of its indications, which may limit its accessibility and broaden the competitive landscape. Despite this, Pfizer’s strong clinical trial portfolio and ongoing evaluations across 18 trials suggest a promising pipeline and potential for expanded indications.

At a glance

Mechanism of action

Prevnar 20 contains purified capsular polysaccharides from 20 different serotypes of Streptococcus pneumoniae, each individually conjugated to CRM197 (a non-toxic variant of diphtheria toxin). When injected, the conjugated polysaccharides are recognised by the immune system. The CRM197 carrier protein enables T-cell-dependent immune responses, producing higher-affinity antibodies and immunological memory compared to unconjugated polysaccharide vaccines.

Approved indications

• Prevention of invasive pneumococcal disease in adults (18+)
• Prevention of pneumococcal pneumonia in adults (18+)
• Active immunisation in infants, children, and adolescents (6 weeks to <18 years)

Pipeline indications

• Immunocompromised adults (CLL, HIV, autoimmune) — phase_3

Common side effects

• Irritability
• Somnolence
• Administration site pain
• Hypophagia
• Pyrexia
• Administration site induration
• Administration site erythema
• Crying
• Diarrhoea
• Administration site swelling
• Vomiting
• Rash

Drug interactions

• Can be co-administered with influenza vaccine and COVID-19 vaccines
• Immunosuppressive therapies may reduce immune response

Patents

Primary sources

Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.

Competitive intelligence

For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape:

• Prevnar 20 CI brief — competitive landscape report
• Prevnar 20 updates RSS · CI watch RSS
• Pfizer Inc. portfolio CI