On Jan. 31 the World Organization for Animal Health released a follow-up report on the new and more virulent bird flu known as H5N9, which was detected in the U.S. for the first time in November at a California duck farm, causing egg prices to soar and new concern for the possibility of a human outbreak. The U.S. had already been dealing with the H5N1 strain that has been spreading in poultry farms and dairy herds, but human infection by this strain has been mostly limited to farm workers who have been in contact with infected animals. This more familiar H5N1 strain can be devastating to a farmer’s livelihood, and potentially life-threatening to humans, however, so far, widespread human infection seems less likely with this strain.