Dr. Esvelt admits flu vaccine is "terrible" - and says there's "no justif

"Flu vaccines tend to be terrible because we often guess wrong," he says.

"As soon as you make a change that doesn't occur in nature, it becomes dangerous because a more pathogenic mutation could then be inserted ... There is no justification for that, because nature will not produce that."

Kevin Michael Esvelt is an American biologist. He is currently an assistant professor at the MIT Media Lab