From Bad to Worse

Chris Bickel

The American Association for the Advancement of Science/AAAS
Washington, DC, USA

The victims are varied, from thousands of sea lions off the coast of Peru to mink farmed for fur in Spain to grizzly bears in Montana and harbor seals in Maine. For that nightmare to unfold, however, the avian flu virus, a subtype known as H5N1, would have to undergo a major transformation, changing from a pathogen efficient at infecting cells in the guts of birds and spreading through feces-contaminated water into one adept at infecting human lung tissue and spreading through the air. Virologists now know that for H5N1 to become adept at spreading between mammals, several of its proteins must evolve. One they are watching closely is the polymerase the virus uses to replicate its RNA genome once it invades a cell. But for H5N1 to cause a pandemic it also needs multiple changes in hemagglutinin, a protein on the surface of the virus that helps it attach to carbohydrates on host cells. Those carbohydrates are shaped differently in birds and mammals, so H5N1's hemagglutinin must change its shape for the virus to efficiently infect mammalian cells.

This illustration captures the anatomy of the H5N1 avian influenza virus and highlights the proteins that would need to undergo alteration and adaptation to increase the infectiousness and ability to translate to a human host. All of the structures in the illustration are produced from protein structural data and are highly accurate yet have been arranged in a precise but pleasing design. Hemagglutinin, the nucleoprotein and the polymerase complex are all structures that would need to morph to allow for H5N1 to cross to humans. Further design on page has produced a lovely interaction and wrap with the body text and makes for a overall pleasing and engaging presentation.

Cinema 4D, Adobe Illustrator, Adobe Photoshop