Nigeria is one of the last remaining strong holds of polio. Whenever the African continent is close to becoming polio free, more cases pop up in Nigeria. Now it’s been reported that there hasn’t been a new polio diagnosis in Nigeria since July, and only six total in 2014—a 90 percent decrease from last year. Hit-and-run vaccination teams, where vaccinators go into warring parts of the country to quickly immunize as many people as possible is a major factor contributing to the decline. Nigeria needs to go three years without a new polio diagnosis to be officially polio free.