Effective, single-dose dengue vaccine developed

Researchers have found promising results from clinical trials on a new dengue vaccine that is very effective at preventing the deadly infection and is likely to require only a single dose.
Approximately 40 per cent of the world's population - 2.5 billion people - are at risk of contracting dengue, a viral infection spread by mosquitoes in tropical and subtropical regions of the world, researchers said.
Dengue fever is best known for producing a high fever, rash and joint pain, but may also cause very serious disease, including hemorrhage and shock, as well as death.
Development of vaccines for dengue has been complicated, since the disease can be caused by any of four dengue virus serotypes and the vaccine must be tetravalent, providing equal protection against all four serotypes, researchers said.

Scientists from University of Vermont (UVM), National Institute of Allergy and Infectious Diseases (NIAID) and Johns Hopkins Bloomberg School of Public Health in the US gave volunteers a vaccine or placebo and tested for protection against a weakened strain of dengue that causes infection, but no or minimal symptoms.
Results showed that all vaccinated volunteers were protected from the "challenge" virus, but none of the volunteers receiving placebo vaccines were protected. The vaccine was well-tolerated in all volunteers.
"This work used a robust method which predicts a high likelihood of success for this critically important dengue vaccine," said Beth Kirkpatrick from UVM.

The findings were published in the journal Science Translational Medicine.