We’re more concerned even than usual, because this bird flu already has developed the genetic capacity to get into a number of other mammals: seals, mink, foxes, cats and most prominently, and unexpectedly

Two cats that belonged to Michigan dairy workers exposed to bird flu died after being infected with the virus last year

As the bird flu outbreak continues to spread among poultry, cows and people, experts discuss the possible need for a bird flu vaccine and if we already have one.