Since the introduction of the Expanded Program on Immunization (EPI) in 1974, considerable progress has been made in achieving broad immunization coverage of paediatric populations in low-income countries. today, 80% of the world's children are vaccinated. Progress has also been made in introducing several vaccines into national immunization programs. Millions of deaths have been prevented. A growing number of diseases are now preventable. One spectacular advance has been the recent control of meningococcal meningitis in the Sahelian belt. Several new vaccines are in the pipeline.
Despite this progress, the challenges remain enormous: polio has still not been eradicated, the cost of vaccines is rising, their storage requires more volume and equipment, and the last twenty percent of coverage is long and difficult to achieve - asymptotic, one might say. The sustainability of the model therefore needs to be consolidated, and geopolitical tensions in the Middle East and Sahelian Africa are not making the task any easier.
