Cryo-EM structure of yellow fever virus

Researchers have captured the first high-resolution images of the yellow fever virus (YFV), a potentially deadly viral disease transmitted by mosquitoes that affects the liver.

They’ve revealed structural differences between the vaccine strain (YFV-17D) and the virulent, disease-causing strains of the virus.

The author said despite decades of research on yellow fever, this was the first time a complete 3D structure of a fully mature yellow fever virus particle had been recorded at near-atomic resolution.

“By utilising the well-established Binjari virus platform developed here at UQ, we combined yellow fever’s structural genes with the backbone of the harmless Binjari virus and produced virus particles that could be safely examined with a cryo-electron microscope,” the author said.

“The particles of the vaccine strain had a smooth and stable surface layer, while the particles of the virulent strain had bumpy uneven surfaces.”

The differences change how the body’s immune system recognises the virus.

“The bumpier, irregular surface of the virulent strains exposes parts of the virus that are normally hidden, allowing certain antibodies to attach more easily,” the author said.

“The smooth vaccine particles keep those regions covered, making them harder for particular antibodies to reach.”

The authors also identify a single residue (R380) in the YFV_17D envelope protein that stabilises the virion surface, and leads to reduced exposure of the cross-reactive fusion loop epitope.

Yellow fever is a major public health concern in parts of South America and Africa and with no approved antiviral treatments, vaccination is the primary means of prevention.

“We can now pinpoint the structural features that make the current vaccine safe and effective.

“The findings could even inform future vaccine design for related viruses like dengue, Zika and West Nile.”

The research was published in Nature Communications.

https://www.nature.com/articles/s41467-025-63038-5

https://sciencemission.com/yellow-fever-virus-envelope-protein