The eradication of smallpox was made possible, mostly because small pox cannot be transmitted by animals or insects. The only carriers of this disease are humans. On the other hand, there have been many efforts to eradicate polio. Although the numbers of children infected with this deforming disease has reduced drastically, it has proven extremely difficult to completely eliminate, due to its rapid ability to spread and the localize outbreak challenges such as water contamination (Beckham, M. 2005).
