New Mouse Model Helps Scientists Test Zika Vaccines

Washington University School of Medicine's research group has built up a mouse model for testing of immunizations and therapeutics to fight Zika virus. Latest outbreak of the infection in South America has incited a few companies to begin developing one.

Vaccines are a typical method for battling mass outbreaks of infections. The Zika virus is from the flavivirus family and there are officially antibodies for a percentage of the infections in its class like yellow fever and Japanese encephalitis according to Science Daily.

"Now that we know the mice can be vulnerable to Zika infection, we can use the animals to test vaccines and therapeutics - and some of those studies are already underway - as well as to understand the pathogenesis of the virus," added senior author and Washington University's professor of medicine, Michael Diamond, MD, PhD.

Analysts in Diamond's research center, led by first author Helen Lazear, PhD, tried five strains of the Zika infection in the mice: the first strain gained from Uganda in 1947; three strains that coursed in Senegal in the 1980s; and the French Polynesian strain, which brought on diseases in 2013 and is almost indistinguishable to the strain bringing on the outbreak. 

"If you take away interferon, the Zika virus replicates quite well in the mouse and goes to the sites that we see it causing disease in humans," said Diamond, a professional in viral immunology and a professor of molecular microbiology and of pathology and immunology.

The immune-deficient mice shed pounds, got lazy and died within 10 days of disease. Ordinary laboratory mice incorporated into the study just created extreme side effects of Zika disease if they were infected not long after birth before their immune system were produced according to News Medical.

"We looked for evidence of Zika in the mouse testes mostly as an afterthought, due to mounting evidence of sexual transmission and were surprised that viral levels were the highest we saw in any tissue," Diamond added. "We are now doing subsequent tests to determine how long those viral levels are sustained, which could help us estimate the length of time Zika can be transmitted sexually."