Zoetis receives conditional license from USDA for vaccines designed to combat avian influenza
                                
                                
                                    (Newser) -
                                    As  bird flu  continues to wreak havoc across the US, killing millions of birds on poultry farms, sending  eggs prices soaring , and even popping up in  cows  and  humans , some good news for chickens: A vaccine against the infectious disease is on the horizon just for them. In a  Friday...