Bobby McFerrin
The reason we don't have a smallpox problem today is because we killed it.Killed it dead by vaccinating virtually everyone in the nation for decades until the disease died out. We didn't get rid of...
Ne t'inquiète pas (de cela). Or ne vous inquiétez pas (de cela). (De cela) is not necessary, but emphasizes the "it" in don't worry about it. Also : Ne t'en fais pas. Ne te fais pas de souci.
Bobby McFerrin wrote the song in 1988.