The microscopic distinctions may explain why dengue sometimes develops into a hemorrhagic fever, while Zika manifests as birth defects, for example, said Michael G. Rossmann, a microbiologist at Purdue University and one of the study’s authors.
“At a lower resolution, many of these viruses just look like matching spherical balls,” said Madhumati Sevvana, the study’s lead author. “Once you zoom in, you start to see the differences in their landscapes.”
The Zika virus is a strong candidate for high-resolution imaging because, compared to other flaviviruses, it is heat-resistant and remains active in varying conditions. That resilience can be detrimental to a feverish patient, but in an imaging lab, it is essential.
“When a virus isn’t stable, it often falls apart on you, and you’re chasing bits and pieces of it instead of the whole thing,” Dr. Rossmann said. “Zika allowed for a homogeneous sample of a flavivirus — and when we understand one a little bit better, we understand them all a bit better.”
The study’s findings likely will not have an immediate impact on disease prevention, according to Kristian G. Andersen, a genomic researcher at the Scripps Research Institute. At present, many promising Zika vaccine candidates cannot be fully tested in humans because of a decline in infections. Bioethicists are conflicted over whether to allow testing in healthy people.
Development of antiviral medicines to treat patients is still in early stages, too.
“Zika has only been under the microscope for the last few years,” said Duane J. Gubler, an emeritus professor of infectious disease at Duke-NUS Medical School in Singapore. “Yes, this is critical information about the structure that is going to be necessary for therapeutics down the road, but I’d add: Don’t hold your breath.”