Major improvement in measles mortality

One of the most depressing problems in public health is that lots of people in developing countries still die of diseases we know how to prevent. In that vein it's really good news that we're making progress on measles:
GENEVA (Reuters) - Worldwide measles deaths had dropped 48 percent in six years as immunization efforts reached more children in sub-Saharan Africa, the United Nations said on Friday.

The World Health Organization (WHO) and U.N. Children's Fund (UNICEF) said the fall in deaths to 454,000 in 2004 from 871,000 in 1999 was "an outstanding public health success story".

"If progress continues at this rate, the global goal to cut measles deaths by half (between 1999 and 2005) will have been achieved in time," said WHO Director-General Lee Jong-wook.

A safe, cheap and effective measles vaccine has been available since the 1960s, but the highly infectious disease is still a major killer of children in developing countries.

What I'd like to know is what we're suddenly doing differently.