Vaccines offer the most cost-effective approach to controlling infectious diseases. Access to vaccines remains unequal and suboptimal, particularly in poorer developing countries. Introduction of new vaccines and long-term sustainability of immunization programs will require proactive planning from conception to implementation. International and national coordination efforts as well as local and cultural factors need to be known and accounted for. Adequate infrastructure should be in place for the monitoring of disease burden, vaccine effectiveness and vaccine safety, based on the common terminology and international consensus. This overview paper aims to raise awareness of the importance of introduction efforts for vaccines of special relevance to resource-poor countries. The target audiences are those involved in immunization programs, from planning or oversight roles to frontline providers, as well as health care professionals.