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It’s an important question that our lab gets asked a lot these days! We wrote an opinion article for the Boston Globe to share our thoughts about why we need to start paying closer attention to bird flu.

The strain known as highly pathogenic avian influenza (HPAI) of the H5N1 subtype has resulted in the biggest wildlife mortality event in history and the expanding host range of the virus poses risks for how the virus jumps into new hosts. Of the 1,000 species of wild birds in the United States, over 150 species have now been infected with H5N1, including iconic species such as Bald Eagles, Red-tailed Hawks, and nesting seabirds, such as Common and Roseate Terns. Check out Figure 1 (made by Jonathan Dain and Melba Torres Sosa, our two new grad students!) to see how the host range of the virus is increasing over time based on USDA data collected over the last two years.

In addition, HPAI H5N1 now has a host range that has expanded beyond the avian reservoir. Infections have been reported in wild mammals ranging from grizzly bears, raccoons, bobcats, and skunks, with red foxes accounting for half of the 110 mammalian infections occurring in the US. Luckily, we have seen only individual mutations and not the required 3 to 5 mutations that would allow HPAI H5N1 to replicate in the upper airways, rather than deeper in the lungs — a transition that would open the door for human-to-human spread. Figure 2 (right side, bottom) shows a possible pathway for bird flu to become a pandemic in humans, involving mutations that change the function and stability of the virus. Becoming a pandemic virus involves a lot of steps, and luckily we are right at the bottom, having only seen mutations in the PB2 and HA genes in either wild or domestic animals.

We also discuss solutions from vaccination to small-scale agriculture and farming of resistant breeds of indigenous poultry in a Nature Magazine article. Stay tuned for updates!