A Louisiana patient is the first person in the U.S. to die from bird flu, health officials said. “Another part of this cancer journey." "I wish I could say this was the worst I’ve ever been treated by a medical professional... but it’s not. It’s just the most ridiculous." The respiratory illness is not new and has previously spiked in the U.S. too.

For influenza viruses, imperfection is a strength. They constantly mutate, producing new strains that challenge immune systems primed to fight earlier varieties. That’s what makes flu a life-long threat to humans and the animal species — mainly birds — that are vulnerable to it.