U.S. to make millions of bird flu vaccine doses this summer, as cases grow

Some 4.8 million doses of flu vaccine are now being prepared for use in response to the growing U.S. outbreak of highly pathogenic avian influenza, or H5N1, officials say. 

The order for the doses to be filled into vials comes as the Centers for Disease Control and Prevention is investigating a growing number of human cases linked to the unprecedented outbreak of the virus in dairy cattle this year. 

The supplies will be pulled from a "pre-pandemic" stockpile funded by the federal Administration for Strategic Preparedness and Response. Vaccinemaker CSL Seqirus has been tasked with manufacturing the doses at its North Carolina plant.