Researchers revealed on Wednesday that an experimental vaccine developed by the U.S. National Institutes of Health was found to be 100 percent effective during its early trials in protecting against the dengue virus.
The vaccine was tested in a double-blind trial study conducted in the U.S. that consisted of 41 healthy participants. The participants were either administered the vaccine or a placebo, and then infected with a mild form of the serotype 2 of the mosquito-borne virus six months later.
The vaccine, called TV003 was created by researched at the NIH from a combination of four strains of the dengue virus. These viruses were weakened, but still live.
Published in Science Translational Medicine, the researchers found that the 20 participants that were given the placebo suffered from minor symptoms associated with the virus, including rashes and a low white blood cell count. The remaining 21 volunteers who were injected with the dengue virus vaccine did not show any symptoms, and blood tests revealed that they were not suffering from the disease.
Even though the study was small, the fact the vaccine was found to be so effective is good news for scientists looking to treat mosquito-borne viruses. The success of the study could help researchers more quickly develop a vaccine against the Zika virus, which is in the same family of viruses as dengue.
The TV003 vaccine was already found to be effective in preventing dengue 1, 3 and 4. To further test the vaccine's effectiveness against dengue 2, researchers at the Butantan Institute in Brazil have already started a larger-scale study, which began last month. Researchers aim to enroll 17,000 adults, adolescents and children for the study by 2018.
The dengue virus is known as the world's most common mosquito-borne virus, infecting approximately 400 million people in more than 120 countries each year. According to the Centers for Disease Control and Prevention, the dengue virus is the leading cause of illness and death in the tropics and subtropics in areas like Latin American and the Pacific Islands. Symptoms include high fever along with a rash, severe headache, eye pain, muscle and/or bone pain, mild bleeding and a low white cell count. Most people develop just a few symptoms, if any at all, although 25,000 people have died from the most dangerous strain of the virus.
There is currently no treatment for dengue, but the vaccine could become available to the public as early as 2018 — if a second trial in Bangladesh that will start in a few months also provides promising results.
Photo: NIAID | Flickr