The US Department of Health and Human Services will award $590 million to Moderna to continue developing a vaccine to protect against bird flu, the pharmaceutical company announced Friday.

As fears grow of a possible bird flu pandemic in humans, the federal government is pouring more money into the development of new vaccines, including an mRNA shot.

The U.S. government has awarded Moderna $590 million to advance the development of its bird flu vaccine, as the country doubles down on efforts to tackle increasing infections in humans. This is in addition to $176 million awarded by the U.

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.

As the Centers for Disease Control and Prevention (CDC) explains, bird flu is a disease caused by the influenza A virus. At the same time, recent CDC data shows that seasonal influenza A is rising across the U.