"Controlling the mosquito vector can work, but it is very expensive and difficult to sustain," says Anna Durbin, M.D., who is leading the study at Johns Hopkins. "In the long run, vaccination would be a more efficient and cost-effective approach."
The new vaccine is tetravalent, meaning that it is designed to protect against all four dengue viruses, also called serotypes. This is especially important because of the way the immune system responds. A person who develops antibodies against one serotype of dengue virus is protected against only that specific serotype. To be fully protected against the four forms of dengue, a person must have antibodies against all four serotypes of the virus. However, having some antibodies to dengue may be worse than having none: Someone who has antibodies against only one or a few of the virus serotypes is actually at higher risk of developing the severe form of the disease upon infection by another serotype. But a person who is immune to all four serotypes cannot be reinfected, and, therefore, is less likely to develop DHF/DSS.
Development of the vaccine was led by Stephen S. Whitehead, Ph.D., and Brian Murphy, M.D., of NIAID's Laboratory of Infectious Diseases. The researchers started by testing seven monovalent vaccines, each of which is designed to protect against a single dengue serotype.
"Our overall strategy was to identify the best individual candidate for each serotype, based on safety and ability to induce an immune response, and to then combine those into a tetravalent vaccine," explains Dr. Whitehead. To optimize the immune response to each dengue serotype, the researchers are testing three different candidat
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| Contact: Nalini Padmanabhan padmanabhannm@niaid.nih.gov 301-402-1663 NIH/National Institute of Allergy and Infectious Diseases Source:Eurekalert |