H5N1 vaccines have been previously licensed, and millions are in the national stockpile. But even with the news of the country’s first human death due to bird flu, vaccination isn’t yet recommended.

The experiment of whether H5 can ever be successful in human populations is happening before our eyes,” Seema Lakdawala, a flu virologist at Emory University, told me. “And we are doing nothing to stop it.

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.

"The Chinese poultry lineage may have experienced more vaccine-driven selection compared to other lineages," the researchers wrote.