Researchers have identified nine mutations in a bird flu strain from a person in Texas. Bad news: this strain is more capable of causing disease and replicates better in the brain. Good news: approved ...

The emergence of the Omicron coronavirus variant, which has set off alarms around the world and has now been detected in the United States, is the result of mutation, a natural process that will ...

The story of the rise and fall of western equine encephalitis as a lethal disease offers essential lessons about how a pathogen can gain or lose its ability to jump from animals to humans. That story ...