Prospects for the use of new vaccines in developing countries: cost is not the only impediment.

Global immunization programs represent a great public health success story. Evidence from every region documents substantial reductions in morbidity and mortality following widespread use of vaccines developed years ago. Development and introduction of new vaccines and vaccine combinations aimed at the industrialized world market are occurring at a fast pace. A number of political and economic factors will influence the rate at which developing country immunization programs incorporate those new vaccines that could have a major public health impact. Perhaps the greatest determinant of this rate is the extent to which international and bilateral agencies and national governments appreciate the potential value of new vaccines.