there is also renewed focus on a vaccine, stephanie stahl has that story. yeah. >>scientists at the university of pennsylvania working on a new bird flu vaccine. >>amounts a very good or elicits a very good immune response, >>immunologist. scott hensley led the study on mice and ferrets. he says with the bird flu now spreading from cows to dairy workers, it's showing signs of mutating >>viruses circulating very widely and birds and cows, and that scares me. because cows are an animal that humans have a lot of contact with what we fear is that the virus will start changing to replicate veteran cows and that some of those mutations that might occur during that process might facilitate better replication in humans. could this turn into another covid? i hope not. but you know, we never really know when a virus is going to make that jump. from other animals into human >>currently, the cdc says the threat to humans is low, but there is high interest in the vaccine that in addition to people might also be used in poultry or dairy cows. this new vaccine is following the