Dr. Gawande retells his experience in India, following Dr. Pankaj as he oversees a massive undertaking: providing immunization to around 4.2 million children in a particular region in India. The amount of preparation required in order for something like this to not be a complete failure is massive, the WHO found success with this endeavor in the Americas... but in the much less modernized and informed parts of India, it's much harder. More than half of the men in some areas are illiterate, as well as more than 3/4s of all women. Between keeping the vaccines fresh and usable in the blistering heat of the desert, the team faced a lot of difficulty getting some of parents to comply. They weren't convinced of what these men were really trying to do, especially considering a lot of children hadn't yet even come into contact with Polio, so the parents saw no need.
Gawande takes great time to explain the inefficiencies of the bureaucratic setup of the WHO. When he and Dr. Pankaj stopped to meet with a doctor that had been stationed to oversee the nearby operations of around 34 thousand children, they found out he was understaffed, lacking enough medicine to go around, and did not have the means of getting the vaccine to everyone in the particular region. He repeatedly mentions past times when people tried to eradicate disease off the face of planet (malaria, hookworms, etc) and failed miserably.
Diligence is necessary in situations like this he argues, when you're trying to get a handful of doctors to cure an entire country of a disease that plagues tens of millions of small children. This is merely a magnified view of what happens inside the hospital on a daily basis.