On April 7, 2019, the World Health Organization (WHO) turned 71—surpassing the proverbial life span of “three score and ten.” Its definition of health as a “state of complete physical, mental and social well-being and not merely the absence of disease or infirmity” has been a guiding framework for the Centers for Disease Control and Prevention (CDC), Pan American Health Organization, and other WHO partners.1(p43) This circa-1948 definition reflected postwar optimism for the control of communicable diseases and the promise of the world’s children. Since then, communicable diseases such as smallpox, polio, diphtheria, and tetanus have been brought under control, infant and childhood mortality have fallen, and life expectancies worldwide have dramatically risen.