In limited study, NIH-developed dengue vaccine proves 100% effective
- The National Institutes of Health (NIH) has developed a vaccine against dengue virus which proved 100% effective in a small trial. All 21 volunteers who received the vaccine were protected from the virus, while all 20 of the placebo-treated patients developed dengue infection.
- Motivated by these promising results, Brazil’s Butantan Institute decided to study the single-dose vaccine, known as TV003, in a large phase 3 trial to further test efficacy. Positive results could lead to the vaccine being made available in 2018, according to Reuters.
- Researchers also hope their experience in developing the TV003 vaccine will inform their efforts to develop a Zika vaccine.
Dengue is considered a public health threat in many of the countries where it's endemic. It infects about 390 million people in more than 120 countries annually. Although most people survive, 25,000 people die each year from dengue hemorrhagic fever.
The vaccine was assembled from four attenuated virus strains. Researchers administered either the vaccine or a placebo, and then exposed both groups to dengue-2 six months later. (The dengue-2 virus only causes mild illness.) All placebo-treated patients had dengue in their blood after exposure, while every vaccine-treated patient was free of infection.
Merck has exclusive rights to the vaccine in the U.S., Canada, China, Japan, and the E.U., setting it up for competition with Sanofi if the vaccine reaches commercialization.
Last December, Sanofi’s Dengvaxia became the first approved dengue vaccine when Mexico gave it a green light. Since then, it has been approved in the Philippines, Brazil, and El Salvador. Further regulatory decisions are pending in 16 other countries.
However, Dengvaxia can only be used with people between the ages of 9 and 45 in places where the virus is endemic.
The NIH vaccine, which has a broader purview, will be tested further in Brazil and Bangladesh. Assuming all goes well, Brazil hopes to have it available by 2018.