The pharmacoeconomics of pneumococcal conjugate vaccines in Latin America

Streptococcus pneumoniae continues to be the most important causative agent of invasive bacterial infections in children and is the most common cause of vaccine-preventable deaths in children less than 5 years of age. Due to some conditions in the Latin America region, economic assessments of pneumococcal conjugate vaccines (PCVs) have unique characteristics. First, distribution of S. pneumoniae serotypes, and thus coverage by vaccines that incorporate certain serotypes, varies within the region and compared with other parts of the world. Second, the mortality rate of pneumococcal infections in developing countries is significantly higher than in the US and Europe. Third, the economies of the Latin American region are very different from those of developed countries. For these reasons, the Pan American Health Organization (PAHO) is promoting the need for economic valuation studies of the impact of pneumococcal vaccines Latin America. Given the importance of pneumonia in the burden of pneumococcal disease in Latin America, the number of pneumonia cases prevented by the vaccine has a large impact on the economic valuation of PCVs, due to a strong correlation with numbers of deaths averted, quality-adjusted life-years (QALYs) gained or disability-adjusted life-years (DALYs) avoided. In terms of cost, analysis of impact on acute otitis media (short-term) and sequelae (long-term) show a significant and important expenditure avoided by vaccination. Cost-effectiveness is significantly modified by vaccine cost, mortality due to pneumonia, vaccine efficacy/effectiveness and herd immunity. Finally the validity of certain assumptions based on the uncertainty of the data should be considered in economic assessments of new PCVs. These include assumptions related to the impact on otitis media, estimates of efficacy/effectiveness based on measured antibody levels and the extrapolation to PCV10 and PCV13 of previous experience with PCV7.