Mass vaccination was the tried-and-true approach to smallpox eradication. Mass vaccination success was measured by the percentage of the population that was vaccinated, in order to achieve herd immunity. Most countries, WHO and other multilateral organizations were committed to this approach and operationally tied the goals to this strategic approach.

Women and their babies were dying from complications of home labor and delivery. Nana and her colleagues were pretty sure that they understood the problem. They thought this was happening because when the women went into labor they had no way to get themselves to their local healthcare facility. They thought that transportation to healthcare facilities that was local, affordable, and accessible was needed. Yet even after MAZA implemented motorized tricycles operated by local drivers in the community to transport women to healthcare facilities, the women were not going to the healthcare facilities.

When HIV first became prominent as a mysterious disease, people had many theories of how it was spread, almost all of them focused on the “immoral and drug-fueled” sexual activities of highly stigmatized groups. They not only held very strong views but they were absolutely certain that they were right. But the public, politicians and scientists were all challenged to rethink their ideas of spread when confronted by reports that the disease could be transmitted by infusing clotting factors from a donor to a patient with hemophilia.

In the early 2000’s WHO had adopted the ambitious goal of getting 3 million people on antiretroviral medicines by 2005. But some people thought this was too ambitious a goal and that it could never be achieved. Leaders were afraid of making a mistake and being wrong, so they were hesitant to act until they were certain they could achieve their goal. Yet waiting would cause costly delays as the disease raged on, and prevent otherwise ambitious and very important programs from making progress.