number had fallen to 118 per 1,000 in low-income countries, and 57 per 1,000
in middle-income countries (though now compared with 7 per 1,000 in highincome
countries and just 4 in many European countries).1 Some important
killers have been completely or nearly eradicated. Smallpox used to kill more
than 5 million people every year; the virus no longer exists outside a few laboratory
samples. Major childhood illnesses such as rubella and polio have been
largely controlled through the use of vaccines. In addition, recent decades
have witnessed a historically unprecedented extension of literacy and other
basic education to a majority of people in the developing world.