This study was conducted at the request of policy makers inThailand to inform decisions about the adoption of PCV as partof this country’s Expanded Program on Immunization (EPI). It wasbelieved that if the vaccine is included in the EPI, its coverage wouldbe almost 100%. Given that Thailand achieves 99% coverage withDTaP 3 dose vaccine [18], such an assumption is not unrealistic.This economic evaluation considered costs and impact of offering10-valent PCV (PCV10), which covers 10 of approximately 90 S.pneumoniae serotypes, or recently licensed 13-valent PCV (PCV13),which covers 3 additional serotypes, compared to the current situ-ation without a PCV program