The idea is biologically plausible and historically grounded — and it reframes how we think about the origin of pandemics.

Global experts urge to prepare for possible new pandemic as new H5N1 bird flu outbreak spreads to dairy animals, human infections. Here's what to know ...

Experts urge US to prepare for possible new pandemic as new H5N1 bird flu outbreak spreads to dairy animals, human infections. Here's what to know ...