A new mouse model developed by scientists at the US Food and Drug Administration may help in exploring the potential activity of Zika virus vaccines and therapeutics. Published in PLoS Pathogens, is the description of a neonatal mouse model that provides a platform for potentially improving and expediting studies to understand the causes and effects (pathology) of the Zika virus.

The recent spread of the Zika virus and its association with increased rates of neurological disorders and complex congenital syndromes, such as microcephaly in babies and Guillain-Barré Syndrome in adults, has created an urgent need for animal models to examine the virus’ pathology. Better understanding the impact and long-term effects of the Zika virus infection in mice may be useful in efforts to find ways to combat it in a human population. While past research indicated that only mice with compromised immune systems are susceptible to Zika virus infection, this study shows that neonatal mice with otherwise healthy immune systems are also susceptible.

"There are many unanswered and essential questions about how the Zika virus works, including the long-term impact," said Daniela Verthelyi, the FDA’s chief of the Laboratory of Immunology, who led the agency's development of the new animal model. "This mouse model gives researchers a new tool to study and understand how the Zika virus replicates and spreads in the body, which we hope will provide these critical answers."

The new animal model described in this publication utilizes the C57BL/6 mouse strain. The FDA’s scientists found that neonatal mice of this strain are susceptible to the Zika virus and develop neurological symptoms 12 days post infection. These mice eventually recover from disease and thus the model provides an opportunity to study the virus’ long-term effects as well as an additional means for early exploration of experimental Zika virus vaccines and therapeutics.

This advancement is just one of many research projects the FDA has undertaken as part of the agency's comprehensive effort to fight the Zika virus. For example, the FDA has invested in initiatives to understand the effectiveness of technologies that reduce pathogens (such as viruses or other microorganisms that can cause disease) in blood, evaluate the impact of red blood cell storage on virus infection, expand the agency’s database of virus-infected samples essential to the development of diagnostic devices, and explore how long the Zika virus persists in body tissues, among other projects.

“The FDA considers the public health response to the Zika virus epidemic to be a top priority. We stand ready to use our expertise and authorities to the fullest extent to help facilitate the development and availability of products that may help mitigate emerging infectious disease threats, such as the Zika virus. The FDA’s regulatory science research program is an essential component of the national response to emerging infectious diseases,” said Luciana Borio, M.D., the FDA’s acting chief scientist. “Helping to advance the approaches scientists can use to understand the Zika virus will ultimately assist in speeding the development and availability of the tools needed to combat it.”

In addition to advancing research initiatives, the FDA is also working rapidly in a variety of areas to respond to the emerging Zika virus outbreak. The agency’s activities are focused on protecting the safety of our nation’s supply of blood and human cells, tissues and cellular and tissue-based products, encouraging development of diagnostic tests to help clinicians detect and diagnose Zika virus infection, and evaluating the safety and efficacy of any investigational vaccines and therapeutics that are currently in various stages of early development.