Mahoney says she can find one reason for the recent outbreak: a new law in her state, like some in other rural states, that allows parents to exempt their children from required vaccinations "because of a personal, moral, or other belief." Mahoney says many rural residents use the exemption, which she finds hard to fathom in the face of scientific advances that prove that vaccination has ended smallpox, wiped out polio in most of the world, and controlled measles, rubella, tetanus, diphtheria, influenza type b and other infectious diseases.
The top map shows the estimated percentage of children enrolled in kindergarten who have been exempted from receiving one or more vaccines in the 2011–12 school year. Comparison with the other map shows that states with large numbers of exemptions are those where whooping cough is making a comeback. (Centers for Disease Control maps)
A comparison between states with low vaccination coverage rates and those reporting higher numbers of whooping cough cases shows some, though not consistent, overlap. (Read more)