The patient in Louisiana who was hospitalized with severe bird flu illness was found to have a mutated version of the virus. Doctors react and share their concerns.

The CDC's analysis revealed changes in the hemagglutinin (HA) gene, a critical component for the virus's ability to attach to host cells. The mutations "were not found in virus sequences from poultry samples collected on the patient's property, suggesting the changes emerged in the patient after infection," the CDC stated in its December 26 update.