Since 2021, experts have seen bird flu — also called H5 influenza or highly pathogenic avian influenza (HPAI) — spreading "fairly quickly" across the wild and domestic bird populations and, now, among dairy cattle, Martinello tells TODAY.com.

Zoetis was granted a conditional license for its avian influenza vaccine for use in chickens. It's a step closer to fighting the bird flu outbreaks that continue to devastate flocks.