A Duke-NUS research team reveals that Zika is more structurally stable compared to similar viruses, and identifies potential sites on the virus to target with therapeutics.
The Zika virus was declared by the World health Organization to be a public health emergency of international concern in February this year, following outbreaks which have been associated with microcephaly and Guillian-Barré syndrome. It is spread primarily by Aedes mosquitos, the same mosquito that transmits dengue, and there is no specific treatment of vaccine currently available.

Associate Professor Shee-Mei Lok and her team from the Duke-NUS Emerging Infectious Diseases Programme have reconstructed a high-resolution image of the Zika virus structure using thousands of cryo-electron microscopy images.

The image revealed that the virus architecture is similar to other flaviviruses, such as the West Nile and dengue viruses. However, the team found that Zika is more stable. Its surface proteins have tighter interactions compared to dengue, which may explain its ability to survive in semen, saliva and urine and spread through sexual contact. It also keeps its structure at 40 degrees Celcius, the body temperature of feverish patients.

These findings suggest that antibodies or drugs that destabilise the structure of the Zika virus may help to reduce the severity of the disease or limit the spread of the virus, providing clues to researchers around the world who are finding therapeutic agents against the Zika viruses.

Prof Lok said, “We have shown that the Zika virus contains structures that are unique from the viruses in the same family that affect brains, such as the West Nile virus, and also those that cause fever, such as the dengue virus. These structures can be mutated to better understand how they influence the Zika virus infection in humans and can also potentially lead to the development of a safe vaccine that has reduced side effects.”
Prof Lok’s next step is to understand the effect of potent antibodies on the Zika virus. By examining the structure presented in this study, her team will work to determine how the antibodies could be used to kill the virus. They also hope to identify which potent antibodies could be used to treat people in emergency situations, such as a sudden outbreak or in the case of infection during pregnancy.