KISSIMMEE, Florida – At the Military Health System Research Symposium, Aug. 17, Lt. Brian Morrison, a scientist from Naval Medical Research Center, presented findings on a pilot study to demonstrate how a humanized mouse laboratory model may help in the development of a vaccine to fight dengue virus.
Fighting dengue is vital to operational health and readiness. This viral infection is spread through mosquito bites and can cause flu-like illnesses with potentially lethal complications. Dengue virus is found globally in tropical and sub-tropical locations where U.S. service members deploy. The global incidence of dengue has grown in recent decades and there is currently no FDA licensed vaccine or antiviral therapy approved for preventing or treating dengue.
“Dengue is the third most important infectious disease threat to U.S. military forces,” said Morrison. “We need an effective laboratory model for testing dengue countermeasures because there are multiple vaccine candidates—some have proved useful, but not ideal—and we need to test all of them, including combinations, to find out what type of immune response each one elicits.”
Morrison’s study seeks to prove that mice with a humanized immune system can improve researchers’ understanding of human immunoprotective and immunopathologic responses to dengue virus.
“The knowledge gained would be critical for dengue vaccine development by the Department of Defense,” said Morrison.
“The immune system is a double-edged sword because it can fight off diseases, but it is also involved in the manifestation of disease symptoms,” said Morrison. “The types of protective responses researchers are looking for when they test vaccines include prolonged survival and decreased clinical symptoms.”
In order to test vaccines to find out if they work, scientists need laboratory models that can exhibit the human immune response, clinical manifestations of the disease, and viremia (the presence of virus in the bloodstream). Essentially, researchers first need to have a laboratory model that can develop a disease as it would in a human in order to find out if a vaccine can prevent it.
Findings from Morrison’s research demonstrated the utility of the humanized laboratory model for dengue virus infection and vaccine studies. According to study findings, the model demonstrated clinical manifestations of dengue virus infection and the virus was found in the bloodstream. But more importantly, specific human antibodies (anti-DENV IgM) were produced in the mice and researchers found human cellular immune responses.
According to Morrison, further studies will investigate characterization of human immune response and vaccine protection.
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