With the rise of dengue cases throughout the world, finding an effective vaccine remains at the top of the list of many health officials. Recently, a new kind of vaccine emerged dubbed the TV003.

It seems to be a promising innovation as initial studies by the National Institutes of Health revealed that the vaccine looks to protect people from at least one type of dengue.

The Vaccine Dengvaxia and Its Limitations

A different vaccine called Dengvaxia has already been licensed and is currently available in other dengue-plagued countries such as Mexico, Brazil, the Philippines and El Salvador. However, further studies have shown that this particular one may not be as effective in cases in the U.S.

Although Dengvaxia was confirmed to bring down the rates of several dengue cases in Asia and Latin America, a lot of the cases had already contracted dengue at a previous point in their lives. More significantly, the vaccine was found to even increase the risk of the virus when given to children who have not yet had the disease in the past. Since much of the country's population belong to this demographic, it's likely Dengvaxia is not a good fit for the U.S.

Research has shown that Dengvaxia is not as effective against the dengue Type 2 as it is for Types 1, 3 and 4.

Creating and Testing a New, More Effective Vaccine

To fill the gaps in the country's vaccination options, the scientists and health officials poured their efforts into finding a better vaccine to protect the population. When they've developed one, they held a different testing method to ensure maximum efficiency.

As published in The Science Translation Magazine, the team employed what's called the "human challenge model," injecting the TV003 to 24 volunteers in Maryland and Vermont. A different set of 24 people received a placebo to stand as a control group. As a result, 92 percent of the participants who got the vaccine developed antibodies to all dengue types.

Six months after getting the vaccine injection, the same participants were infected artificially with a weakened version of dengue Type 2, to target the particular weakness of Dengvaxia to this type. Amazingly, none of the vaccinated volunteers got infected by the dengue virus.

Although the ethics of such human challenge testing can be controversial, the effectiveness shows the risk might have paid off.

"The results of this work are very straightforward and quite conclusive," Beth Kirkpatrick, a professor of medicine at the University of Vermont, said. "The bottom line is that the vaccine appears to be 100 percent efficacious."

The large-scale testing for Phase 3 of the vaccine has already begun in Brazil with a target 17,000 participants and projected completion in 2018.

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