More must be done to target the 22 million children, mainly in the poorest countries, who do not have access to lifesaving vaccines that protect against diseases such as measles, pneumonia and rotavirus, writes Microsoft cofounder Bill Gates.

Since we can't be sure whether one poor country’s GDP is higher than another’s, we should not use GDP alone to determine which policies lead to growth.

Progress in getting aid to the world's poorest is now measured by one improved life at a time. That kind of news still lacks the visibility of a big setback.