Cost-effectiveness of alternative strategies for use of 13-valent pneumococcal conjugate vaccine (PCV13) in Canadian adults

Objectives The Canadian National Advisory Committee on Immunization (NACI) recommends use of 13-valent pneumococcal conjugate vaccine and 23-valent pneumococcal polysaccharide vaccine in a sequential schedule (PCV13 -> PPV23) among adults aged >= 65 years and those aged >= 18 years who are immunocompromised. In light of recent PCV13 efficacy data from the Community-Acquired Pneumonia Immunization Trial in Adults (CAPiTA), and new sero-epidemiology data on community-acquired pneumonia (CAP), we examined the economic implications of finding an expanded adult pneumococcal immunization program in Canada. Methods A microsimulation model depicting expected lifetime risks, consequences, and costs of invasive pneumococcal disease (IPD) and CAP was developed. PPV23 effectiveness was based on published literature, and PCV13 effectiveness was based on CAPiTA; all other model parameters were based on published data or secondary sources. Herd effects from the PCV13 pediatric program were considered. Outcomes and costs were evaluated assuming use of PPV23 alone, and alternatively, use of PCV13 -> PPV23 among (1) all adults aged >= 65 years (n = 5.4 M) and (2) immunocompromised and high-risk adults aged >= 65 years (n = 3.0 M). Results For population no. 1, PCV13 -> PPV23 reduced IPD cases by 1100, CAP cases by 7000, and disease costs by $135.8M; vaccination costs increased by $254.3M, and cost per QALY gained was $35,484. For population no. 2, PCV13 -> PPV23 reduced IPD cases by 900, CAP cases by 6000, and disease costs by $120.3M; vaccination costs increased by $149.8M, and cost per QALY gained was $10,728. Conclusion Expanding use of PCV13 -> PPV23 by funding PCV13 among Canadian adults aged >= 65 would be a cost-effective use of healthcare resources.