The five health care employees had been definitively seronegative from H5 in all assays, meaning they were not contaminated with H5. This examine demonstrates a development of weakening binding affinity of present antibodies towards H5 isolates over time, indicating the H5N1 virus is evolving immune escape of our health-related defenses. https://www.dailypioneer.com/2014/sports/2014-05-31-49739.html