Experimental dengue vaccine protects all recipients in virus challenge study

A clinical trial in which volunteers were infected with dengue virus six months after receiving either an experimental dengue vaccine developed by scientists from the National Institutes of Health (NIH) or a placebo injection yielded starkly contrasting results. All 21 volunteers who received the vaccine, TV003, were protected from infection, while all 20 placebo recipients developed infection. The study, published in Science Translational Medicine, underscores the importance of human challenge studies, in which volunteers are exposed to disease-causing pathogens under carefully controlled conditions. “The findings from this trial are very encouraging to those of us who have spent many years working on vaccine candidates to protect against dengue, a disease that is a significant burden in much of the world and is now endemic in Puerto Rico,” said Stephen Whitehead, Ph.D., of NIH’s National Institute of Allergy and Infectious Diseases (NIAID). “In fact, these results informed the recent decision by officials...