Drug target for dengue vaccine identified

In a breakthrough, scientists have identified a new drug target for the deadly dengue virus, paving way for potential vaccines for the world's most widespread mosquito-borne disease.
Using an experimental technique new to the dengue field, researchers showed that a molecular hinge where two regions of a protein connect is where natural human antibodies attach to dengue type-3 to disable it.
The finding by researchers at the University of North Carolina shows that most human antibodies that neutralise the virus bind to this hinge.
It's the first study to demonstrate how these binding sites can be genetically exchanged without disrupting the integrity of the virus, researchers said.

"This gives us a lot of insight into how human antibodies work," said Aravinda de Silva, a professor of microbiology and immunology in the UNC School of Medicine.
"And there could be a lot of translational aspects to this; it could lead to a new way to create vaccines for other diseases," said de Silva.

De Silva and Ralph Baric are working with vaccine developers at two pharmaceutical companies to test the effectiveness of potential dengue vaccines now in clinical trials.
Dengue, which infects approximately 390 million people each year, is common in tropical and subtropical regions around the world, researchers said.

Making a truly effective dengue vaccine has proven difficult because of a phenomenon called antibody dependent enhancement.
People infected with one type of dengue usually develop a natural immune response that rids the body of the virus and prevents a repeat infection of that same virus type.
But if those people are infected with a second type of dengue, the virus is enhanced because of that first immune response.
The result can be severe dengue hemorrhagic fever, which can be deadly.
The study was published in the journal PNAS.