Fig. 1

Flowchart of study selection. The following search terms were used: [Streptococcus pneumoniae OR pneumococcus OR pneumococcal OR pneumococci OR PCV OR pneumococcal conjugate vaccine] AND [(vaccin* adj3 policy) OR (vaccin* adj3 policies) OR (vaccin* adj3 implement*) OR (vaccin* adj3 progra*) OR (immun* adj3 progra*) OR (immun* adj3 implement*) OR (immun* adj3 policy) OR (immun* adj3 policies)] AND [middle income country OR middle income countries OR developing econom *]