The U.S. will rebuild its stockpile of bird flu vaccines for poultry matched to the current strain of the virus circulating among commercial flocks and wild birds, the Department of Agriculture said on Wednesday.

Medical experts advise that people should get a vaccine for the bird flu when it becomes commercially available. One doctor said the most at-risk patients should be first.

CDC officials say medical professionals are seeing more patients whose illness cannot be traced back to an infected animal or bird.

NBC News Medical Contributor Dr. Kavita Patel speaks with Gadi Schwartz about the difference in symptoms between a cold and the flu and explains the CDC's urge for faster testing to find human bird flu cases.

The risk to the general public from bird flu is low, and there has been no further evidence of person to person spread, the agency said. Influenza A-positive patients, particularly those in an intensive care unit,

CDC officials say they extended the guidance now because they are seeing more H5N1 patients whose illness they cannot track back to an infected bird or cow.

Spartanburg has a confirmed case of the bird flu. The CDC reports the virus was detected on Dec. 31, 2024, in a flock of about 490 birds.