Worldwide control of disease through immunization. Progress and prospects.

In summary, tremendous advances have been made over the past 15 years toward the development of effective national immunization programs throughout the world. Immunization levels among children in the developing world have risen dramatically, and in some instances, now equal or exceed levels in industrialized nations. There is no room for complacency, however, because millions of children remain incompletely immunized and many die each year from measles, pertussis, and neonatal tetanus. Immunization activities need to be intensified, accelerated, and sustained within the context of the primary health care system. Expansion of immunization programs to include additional vaccines and other simple health interventions will yield further benefits in the years ahead.