An experimental vaccine for dengue fever had a protection rate of 100 percent, researchers at the U.S. National Institutes of Health (NIH), who conducted a small trial, reported. They added that the vaccine has the potential to be used on a global level by 2018.
For the study, the researchers recruited 41 volunteers - 21 were given a single dose of the experimental vaccine TV003, while the remaining 20 received a placebo injection. All of the volunteers were then exposed to the dengue-2 virus strain six months later. The researchers found that TV003 protected every single participant that took it from being infected.
The volunteers from the placebo group, however, did not fare as well. Every single person was infected by the virus. Eighty percent developed a mild rash and 20 percent had a reduced white blood cell count.
"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 of the NIH's National Institute of Allergy and Infectious Diseases (NIAID). "In fact, these results informed the recent decision by officials at Brazil's Butantan Institute to advance the TV003 vaccine into a large phase 3 efficacy trial."
The Butantan trial, which aims to enroll 17,000 participants, will test the effectiveness of the vaccine in naturally occurring cases of dengue.
"Knowing what we know about this new vaccine, we are confident that it is going to work," said Dr. Anna Durbin, who has been working on a dengue vaccine for more than a decade. "And we have to be confident: Dengue is unique and if you don't do it right, you can do more harm than good."
The NIH researchers hope that the success from this vaccine could offer insight into creating a vaccine for the Zika virus, which has been spreading at high rates in the Caribbean and Latin America. Both viruses are transmitted by the Aedes aegypti mosquito.
TV003 was made from a combination of four live but weakened viruses that targeted the four strains of dengue.
The study's findings were published in Science Translational Medicine.
