Cost-effectiveness and public health impact of 24-valent pneumococcal conjugate vaccine compared to recommended pneumococcal vaccines in older adults

Introduction: The potential impact of an in-development 24-valent pneumococcal conjugate vaccine (PCV24) compared to currently recommended vaccines in older adults is unclear. Similar to most currently available PCVs, PCV24's formulation is based on childhood pneumococcal disease epidemiology. Decision analysis techniques were used to estimate PCV24 cost-effectiveness and public health effects in US older adults.

Methods: A Markov model compared PCV24 to currently recommended US pneumococcal vaccination strategies in older adults (aged ≥65 years) and to no vaccination. Age-, race-, and chronic medical condition-specific pneumococcal illness risks and serotype-specific disease risks were obtained from CDC data. Vaccine effectiveness was estimated using Delphi panel and clinical trial data. Vaccination and pneumococcal illness costs were from US databases. Scenario analyses examined indirect effects of childhood pneumococcal vaccination on adult disease. Data were collected and analyses performed in 2024.

Results: PCV24 prevented fewer pneumococcal disease cases and deaths than the recently recommended 21-valent pneumococcal conjugate vaccine (PCV21), which is formulated based on adult pneumococcal disease serotypes. In cost-effectiveness analyses, PCV21 was economically favorable compared to PCV24 and all other vaccination strategies, both without and with consideration of potential childhood vaccination indirect effects. These findings were robust and consistent in deterministic and probabilistic sensitivity analyses.

Conclusion: In older adults, PCV24 was clinically and economically unfavorable compared to PCV21, which covers more adult disease-causing pneumococcal serotypes and is less susceptible to childhood vaccination indirect effects.