New Dengue Virus Vaccine Shows Promise
Research may also aid in development of Zika virus vaccine, expert suggests
By Alan Mozes
WEDNESDAY, March 16, 2016 (HealthDay News) -- An experimental vaccine against dengue -- the mosquito-borne virus behind a very painful illness -- was found effective in a new study.
In the small trial involving just 41 healthy volunteers, one dose of the "TV003" vaccine offered 100 percent protection against a particularly tricky strain of the disease that scientists initially thought might be outwitting the vaccine.
Coupled with earlier indications that the vaccine also offers strong protection against three other strains of dengue, the results bode well for ongoing efforts to control the most widespread mosquito-transmitted virus in the world, the researchers said.
"Development of vaccines for dengue has been complicated, since disease can be caused by any of four dengue virus serotypes [strains]," explained study author Dr. Beth Kirkpatrick, director of the Vaccine Testing Center in the department of medicine at the University of Vermont College of Medicine in Burlington.
And a truly effective vaccine must provide "equal protection against all four," she added. That's because if someone who has been sick with one strain of dengue gets infected with a different strain, the second strain will cause more serious illness, she explained.
Kirkpatrick described the current findings as "encouraging," though she stressed that more research, on a larger scale, will be needed to confirm the vaccine's promise.
The study was published online March 16 in the journal Science Translational Medicine.
Dengue strikes roughly 390 million people each year, primarily in tropical and sub-tropical environments, according to the study authors.
Most infections are actually mild or without symptoms, the researchers noted.
But upwards of 2 million of those infected end up with dengue hemorrhagic fever, the study authors said. Symptoms include a very high fever, severe headaches, muscle and joint pain, blood vessel leakage and circulatory failure, according to the U.S. Centers for Disease Control and Prevention. For roughly 25,000 patients a year, the disease is fatal.
The new vaccine covers all four strains of dengue. It was first tried out in early 2016, with availability confined to just three countries: Mexico, the Philippines and Brazil, according to the study authors.