There was an article in "Rolling Stone" several years ago, about the Spanish Influenza. The suggestion was that it might come back, and do more damage. I've also seen a PBS documentary of people excavating the graves of people who died of the flu in Scandinavia and Alaska, on the theory that he permafrost might have preserved the virus.
This doesn't mean I think we need the damn virus! I don't think it could be controlled.
My father and his brothers survived the 1918 epidemic. Though my granparents were told that dad would be a permanent invalid, because of the damage the flu did to his lungs. (The "permanent invalid" was on his high school track team, and won a medal in the Penn Relays.)