Since 2001, the Measles Initiative has vaccinated one billion children in 60 developing countries. Their efforts reduced measle deaths by 78%. That's progress but it only takes one unvaccinated child to spawn a measles outbreak. Like the 7-year old patient of Dr. Sears, author of The Vaccine Book*, who returned to California from Switzerland with measles thus creating the worst measles outbreak in the US since 1989 at a cost of $10 million dollars. (Seth Mnookin, The Panic Virus, p. 271)
*Not to be confused with a book that roundly dismisses the autism-vaccine link.