In March 2016, Shannan Rossi, a virologist at the University of Texas Medical Branch, has declared that the campaign to suppress the rapid proliferation of the Zika virus got a much needed push through the first peer-reviewed publication of a mouse model of the infection reported for decades.
Together with vector biologist Scott Weaver, a UTMB colleague, the two have been in the forefront of investigations due to the proliferation of the infection across Central and South America.
As early as 2009, Weaver, who is an expert in mosquito-borne viruses that cause dengue, West Nile and yellow fever, has warned that Zika presented a threat. Due to the urgency of the situation, a study involving mice has been put together in weeks.
The research team has reported that low immunity played a critical factor in the progression of the viral infection. Mice, which had been genetically altered to have a deficient innate immune response, have become susceptible to the contagion.
Based on this approach, it has been observed that young mice become lethargic and eventually died within six days. Older mice have also got sick but managed to recover. Dr. Pei-Yong Shi, another UTMB member, has come up with an antiviral treat dengue fever using the model.
Considering that very little information is known about how the Zika virus operates inside the body, researchers checked the animals' organs and found most of the particles in the spleen, brain and testes. The findings can provide a breakthrough in understanding the incomplete brain development, also known as microcephaly, in infected mothers.
Thomas Friedrich, an Associate Professor at the University of Wisconsin, and his team have used macaques to better understand how the virus works. He says that different animal models are useful for different questions. Monkeys, which are naturally infected by the Zika virus, can be utilized to monitor an immune response. Whereas the mice need to be immuno-compromised to be infected, the monkeys don't. According to AB Failloux, a researcher, mice are not natural carriers so their immune system needs to be shut down in order for the virus to inoculate the animals. Viral immunologist Michael Diamond of Washington University shares that mice cannot sustain a Zika infection because the virus triggers interferons that bolster immune responses. Pregnant mice treated with antibodies have managed to control the infection and allowed their young to survive.
