Though it's illegal to sell raw milk across state lines, since 1949 it's been legal to sell raw milk cheese provided it has been aged for at least 60 days. That period allows for development of natural acids and enzymes that have been thought to destroy pathogens.

Raw cheese made with milk from dairy cattle infected with bird flu can harbor infectious virus for months and may be a risk to public health, according to a new study from researchers at Cornell University that was funded by the US Food and Drug Administration.

Scientists already discovered that raw milk can harbor the infectious H5N1 bird flu virus, but now there’s a new study on its capabilities that has health officials concerned.