H5N1—also known as bird flu—continues to spread among animals and, for the first time, is spreading among cows. Thankfully, the risk to the public is low, but the more the virus spreads, the more chances it has to mutate and jump species to spread among humans. Given H5N1’s high mortality rate, we don’t want this to happen. Here’s what we know and don’t know. Note: We on the yalesph team are happy to share that we’re partnering with your_local_epidemiologist on this post to amplify her important public health communications work. Information in this post is from the Your Local Epidemiologist newsletter on Substack. Read and subscribe to the newsletter for a deeper dive on where we are with bird flu and much more.