Experimental Dengue Vaccine Protects Every Participant in Small-Scale Trial

By Jamie Condliffe on at

An experimental vaccine for Dengue fever has been tested on participants who were all exposed to the virus—none of whom went on to show any signs of illness.

The new vaccine, known as TV003, was developed by National Institutes of Health. During a double-blind trial each participants received either a placebo or the vaccine. When infected with a mild form of Dengue, the 20 who had received the placebo developed symptoms of the disease and low white blood cell count indicative of infection. Meanwhile, the 21 who received the vaccine showed no sign of infection. In other words, 100 percent of vaccinations were successful. The results are published in Science Translational Medicine.

The US Centers for Disease Control and Prevention estimates that more than 400 million people are infected with the virus each year, with a half-million going on to develop severe haemorrhagic dengue fever. That causes about 25,000 deaths per year, and the viruses reach is widening.

Other Dengue vaccines already exist. Notably, Dengvaxia is already being rolled out in some countries. It’s already passed through extensive testing, with 29,000 participants having received the vaccine during trials—though it isn’t perfect. It’s effective for about 65-per cent of people aged 9 to 16, but can’t be used on younger children or those over 45.

The new vaccine could prove more effective, but there’s still a way to go. The good news that it’s already entering the next phase of research in Brazil. The team is hoping to recruit 17,000 participants across the country and hopes to complete the study by the end of 2018. If that goes well, it may be put to use around the world. The other option, of course, is to declare war on mosquitoes.

[Science Translational Medicine via Washington Post]

Image by Tom