H5N1

The concerning bird flu outbreak that has spread to four humans so far as it expands quickly in the U.S. has jumped to dozens of species, infecting mammals in at least 31 states.Among those infected are cows in 12 states, foxes, mice,…

The discovery of H5N1 bird flu in U.S. cattle — and the news that at least one person in Texas has been infected, apparently through contact with infected cows — has taken scientists who study influenza by surprise. But after absorbing…