A promising dengue vaccine

The medical community is one step closer to a vaccine that protects against dengue, a mosquito-borne illness, closely related to the Zika virus, that kills some 25,000 people a year worldwide. In a clinical trial, researchers tested an experimental vaccine called TV003 that was developed at the National Institutes of Health. They infected 41 volunteers with a weakened version of dengue and gave the vaccine to 21 of them. All members of the unvaccinated group showed mild signs of dengue, notably a characteristic rash, but the vaccine proved 100 percent effective—none of the 21 people who received TV003 became sick. The results are so promising that large-scale tests of the vaccine have already begun in Brazil. “We are confident that it is going to work,” researcher Anna Durbin, an infectious-disease specialist at Johns Hopkins University, tells NBCNews.com. If the dengue vaccine proves safe and effective, she adds, it could provide a valuable shortcut for researchers working to develop a vaccine that protects against Zika, which has been linked to serious birth defects and neurological complications.