https://phys.org/news/2018-05-scientists-zika-virus.html

To combat this issue, scientists are actively exploring the development of a virus-induced disease in animal models, for example, in mice. However, healthy mice are resistant to human-like infection symptoms. Therefore, mice with mute immune response genes are usually used to study the virus. Such models are not very effective, as they cannot accurately reflect what happens when a human is infected.

A research group from the University of Washington in St. Louis and ITMO University has solved this problem by making mice more vulnerable to the disease and the virus itself more infectious for mice. "One of the key targets for the Zika virus is the transcription factor STAT-2, which triggers an antiviral immune response. Ordinary mice are resistant to the virus since their version of this factor does not bind with viruses. Our colleagues succeeded in replacing the mouse STAT-2 with a human one. What is more, they adapted the virus for mice. As a result, we got a relatively healthy mouse in which the disease developed as it does in humans. And like humans, it is able to transmit the virus to its offspring through the placenta," says Professor Maxim Artyomov from the University of Washington in St. Louis.