Avian influenza can and does affect humans. There have been fatal cases, especially in developing nations. We also don't want avian influenza in humans (whether it makes them sick or not) because the avian genes might combine with a human strain, and then we have a pandemic.

As for your assertion on bioavailability, I mentioned that in the story. Sorry you missed it. And I'll take my own doctoral degree in epidemiology, master's in public health, and bachelor's in medical technology, and all the biology courses that came with them, over an infographic from an unsourced website. Thanks!