PIN7 COST-Effectiveness Analysis Of Anti-Pneumococcal Vaccines Versus No Vaccination In El Salvador

Abstract

In 2009, it was estimated that there were 12.000 to 28.000 deaths in Latin America related to Streptococcus pneumonia infections in pediatric population under 5 years old. Currently, in El Salvador, Prevenar 7 (PCV-7) is the anti-pneumococcal vaccine used. The aim of this study was to estimate the cost-effectiveness and cost-utility of immunization strategies based on pneumococcal conjugated vaccines (PCVs) in El Salvador, from an institutional perspective. A decision tree model was used to asses economic and health impact of PCVs in children under 2 years old. The alternatives compared were: no vaccination (comparator), PCV-7, PCV-10 and PCV-13. The effectiveness measures were: child illness avoided, life years gained (LYs) and quality-adjusted life years (QALYs) gained. Effectiveness and utilities were obtained from literature. Local costs (expressed in 2009 $US) and epidemiology (data from 2009) were obtained from El Salvador′s Ministry of Health database. The model included vaccine dosage schedules approved in WHO prequalification and/or El Salvador MoH calendar at the time of data collection (dec-2010). Univariate sensitivity analysis was performed. The time horizon was one year and the discount rate was 3%. Results show that immunization is cost-saving against no-vaccination. PCV-13 gained the highest number of QALYs (898) against PCV-10 (637) and PCV-7 (460). PCV-13 prevented 359 illnesses and gained 998 LYs. PCV-10 and PCV-7 prevented 257 and 228 illnesses and gained 707 and 511 LY′s, respectively. These results were robust to variations in herd immunity and impact adjustments of PCV10 immunogenicity. In El Salvador, immunization strategies based on 7, 10 and 13-valent PCV′s would be cost-saving interventions. Health outcomes and savings of PCV-13 are greater than those estimated for 7 and 10-valent PCV′s.