Viral skin diseases like smallpox were among the first diseases to be eradicated through vaccination program, but now we see more outbreaks of measles, mumps and polio diseases for which we have vaccinations. Why do you think some diseases are appearing again? What is your understanding about diseases like malaria and Ebola, and can we eradicate these through vaccination programs? What is the role of CDC in controlling the spread of these communicable diseases and their treatment?