Cost Effectiveness of Pneumococcal Vaccination in Children in Low- and Middle-Income Countries: A Systematic Review

BACKGROUND: Although pneumococcal conjugate vaccines (PCVs) have been available for prevention of invasive pneumococcal disease (IPD) caused by Streptococcus pneumoniae (S. pneumoniae) for over a decade, their adoption into national immunization programmes in low- and middle-income countries (LMICs) is still limited. Economic evaluations (EEs) play a crucial role in support of evidence-informed decisions.

OBJECTIVE: This systematic review aims to provide a critical summary of EEs of PCVs and identify key drivers of EE findings in LMICs.

METHODS: We searched Scopus, ISI Web of Science, PubMed, Embase and Cochrane Central from their inception to 30 September 2015 and limited the search to LMICs. The search was undertaken using the search strings 'pneumococc* AND conjugat* AND (vaccin* OR immun*)' AND 'economic OR cost-effectiveness OR cost-benefit OR cost-utility OR cost-effectiveness OR cost-benefit OR cost-utility' in the abstract, title or keyword fields. To be included, each study had to be a full EE of a PCV and conducted for an LMIC. Studies were extracted and reviewed by two authors. The review involved standard extraction of the study overview or the characteristics of the study, key drivers or parameters of the EE, assumptions behind the analyses and major areas of uncertainty.

RESULTS: Out of 134 records identified, 22 articles were included. Seven studies used a Markov model for analysis, while 15 studies used a decision-tree analytic model. Eighteen studies performed a cost-utility analysis (CUA), with disability-adjusted life-years, quality-adjusted life-years or life-years gained as a measure of health outcome, while four studies focused only on cost-effectiveness analysis (CEA). Both CEA and CUA findings were provided by eight studies. Herd effects and serotype replacement were considered in 10 and 13 studies, respectively. The current evidence shows that both the 10-valent and 13-valent PCVs are probably cost effective in comparison with the 7-valent PCV or no vaccination. The most influential parameters were vaccine efficacy and coverage (in 16 of 22 studies), vaccine price (in 13 of 22 studies), disease incidence (in 11 of 22 studies), mortality from IPD and pneumonia (in 8 of 22 studies) and herd effects (in 4 of 22 studies). The findings were found to be supportive of the products owned by the manufacturers.

CONCLUSION: Our review demonstrated that an infant PCV programme was a cost-effective intervention in most LMICs (in 20 of 22 studies included). The results were sensitive to vaccine efficacy, price, burden of disease and sponsorship. Decision makers should consider EE findings and affordability before adoption of PCVs.