Bird flu (H5N1) has been spreading among dairy cows in the US, with reports of human infections raising concerns about potential human-to-human transmission. The virus, responsible for millions of bird deaths globally, has infected 14 people in the US since March, with one recent case in Missouri showing no known animal contact, suggesting rare mutations. Virologists warn that the virus's spread in cattle and potential transmission through migrating birds could lead to a global pandemic. Despite the CDC's assurance that the risk to the public remains low and the latest Missouri case may be a one-off, experts call for increased vigilance and aggressive screening due to the virus's high human fatality rate and ability to mutate.