Dengue Fever Vaccine Breakthrough, Proves 100% Effective In Human Trials

Dengue fever isn't heard of very often in America but it has plagued the southern hemisphere for decades, reaching epidemic levels in many countries, infecting between 50 million and 528 million people yearly and more than 1 in 14 people worldwide. The World Health Organization estimates that around 500,000 are hospitalized by the disease every year, many of them children.

Also known as "breakbone fever," research into a cure for the mosquito-borne infection has been largely fruitless, and efforts to control dengue fever have focused on controlling mosquito populations.

Until now.

According to a report from Wired UK, America's National Institute of Allergy and Infectious Disease (NIAID) has carried out a successful clinical trial of a dengue fever vaccine with success rates of 100 percent.

And while the trial was too small to determine if the vaccine is truly absolute, consisting of only 21 subjects, and another 20 in a control group, the experimental TV003 gives hope that the world may finally be able to not just prevent, but eradicate dengue fever.

Workers in Japan spray pesticides to kill mosquito populations after a dengue fever outbreak.
Workers in Japan spray pesticides to kill mosquito populations after a dengue fever outbreak. [Photo by Chris McGrath/Getty Images]According to RT, last year, 48 volunteers were injected with either a placebo or the TV003 vaccine by researchers from the University of Vermont and Johns Hopkins in Baltimore. Six months later, 41 of the volunteers were brought back to the lab, and all were exposed to a modified strain of the most aggressive form of dengue fever, first identified in Tonga in 1974. The research strain still shows up in blood tests and causes the characteristic rash of dengue, but does not cause other complications, so as to not put the volunteers at risk.

The results were startling, even to the researchers.

Every member of the placebo group showed the virus multiplying in their bloodstream, and 16 of the 20 developed the signature rash.

Of the vaccinated subjects, not one suffered any form of the infection. Beth Kirkpatrick, a professor of medicine at the University of Vermont, said in a conference call that "the results of this work are very straightforward and quite conclusive."

"The bottom line is that the vaccine appears to be 100 percent efficacious."
The trial was so successful, researchers are already looking into using a modified form of the vaccine to treat the related Zika virus, a related, if less severe, infection which has also reached epidemic levels multiple times in the past several years. A widespread outbreak of the Zika virus is currently underway in South and Central America. The WHO has warned that the outbreak is likely to spread throughout most of the Americas by the end of the year; but, if the TV003 vaccine proves as effective against Zika as it has against dengue, that outbreak may be stopped in its tracks.

Dr. Anna Durbin, Associate Professor at Johns Hopkins Bloomberg School of Public Health, was also pleased and surprised by the results.

"We were pleasantly surprised to see that this candidate vaccine provided complete protection in everyone who received it. The dengue-2 serotype is considered the relatively weaker component in this, and other, candidate dengue vaccines, so its ability to confer protection from a challenge with dengue-2 virus was encouraging."
Dengue has much in common with the common cold and influenza; it's not just a single disease, but a combination of interrelated strains, making treatment difficult. While not subject to the extreme variety and mutability of colds and flus, the success of the dengue fever vaccine may give scientists some hints on how to treat America's most ubiquitous infections going forward.

Most importantly, unlike the previous most-effective vaccine for dengue, TV003 does not suppress immune response. The recently-approved Dengvaxia can actually worsen the impact of dengue on children under nine, who are already most at risk, and offers no more than 75 percent protection against any strain --particularly not the dengue-2 strain TV003 was tested against.

Dengue fever is responsible for tens of thousands of deaths every year - most among young children.
Dengue fever is responsible for tens of thousands of deaths every year - most among young children. [Photo by Dimas Ardian/Getty Images]Brazilian researchers were so impressed that a massive Phase 3 trial is already underway in Brazil, treating 17,000 subjects with the vaccine and scheduled to end in 2018.

Given the success of TV003 thus far, it's likely that the public see the vaccine fast-tracked to market and dengue stopped in their lifetimes.

[Photo by Dimas Ardian/Getty Images]