Introduction: In 2012, the Advisory Committee on Immunization Practices (ACIP) revised recommendations for adult pneumococcal vaccination to include a sequential regimen of 13-valent pneumococcal conjugate vaccine (PCV13) followed by 23-valent pneumococcal polysaccharide vaccine (PPSV23) for certain high-risk adults with immunocompromising conditions. This study, from a payer perspective, examined: (1) the cost-effectiveness of the new 2012 ACIP vaccine policy recommendation relative to the 1997 ACIP recommendation; (2) the cost-effectiveness of potential future pneumococcal vaccination policies; and (3) key assumptions that influence study results.
Methods: A static cohort model that incorporated costs, health outcomes, and quality-adjusted life-year (QALY) losses associated with invasive pneumococcal disease and non-bacteremic pneumococcal pneumonia (NBPP) was developed to evaluate seven pneumococcal vaccination strategies for a 50-year-old adult cohort over a 50-year period using incremental cost-effectiveness ratios (ICERs).
Results: For objective 1, the 2012 ACIP recommendation is the more economically efficient strategy (ICER was $25,841 per QALY gained vs. no vaccination). For objective 2, the most efficient vaccination policy would be to maintain the 2012 recommendation for PPSV23 for healthy and immunocompetent adults with comorbidities, and to modify the recommendation for adults with immunocompromising conditions by replacing PPSV23 with a sequential regimen of PCV13 and PPSV23 at age 65 (ICER was $23,416 per QALY gained vs. no vaccination). For objective 3, cost-effectiveness ratios for alternative pneumococcal vaccine policies were highly influenced by assumptions used for vaccine effectiveness against NBPP and accounting for the herd protection effects of pediatric PCV13 vaccination on adult pneumococcal disease.
Conclusion: Modifying the 2012 recommendation to include an additional dose of PCV13 at age 65, followed by PPSV23, for adults with immunocompromising conditions appears to be a cost-effective vaccine policy. Given the uncertainty in the available data and the absence of key influential data, comprehensive sensitivity analyses should be conducted by policy-makers when evaluating new adult pneumococcal vaccine strategies.