Rapid improvements in health and nutrition in developing countries may be ascribed to specific, deliberate, health- and nutrition-related interventions and to changes in the underlying social, economic, and health environments. Consideration of the environment as the context for interventions is crucial in determining their initiation and in modifying their effect, and it must be taken into account when assessing this effect. Undoubtedly much change has stemmed from scientific advances, immunization being a prominent case. However, the organizational aspects of health and nutrition protection...