There's new hope for those who suffer from dengue, a virus characterized by hammering headaches, high fevers and pain. A vaccine shows promise after a two-year trial in five Asian countries.
Dr. Maria Rosario Capeding, one of the researchers in the Philippines, said that during the trial, the vaccine cut the number of dengue cases in half and significantly reduced the number of severe cases that cause hemorrhaging.
"The vaccine efficacy against dengue hemorrhagic fever, according to the WHO criteria, after three doses was 88.5 percent," she said.
Another large scale study is taking place in Latin America. Sanofi Pasteur, the manufacturer, says the vaccine could be available by 2015. The study was published in The Lancet medical journal.
Dengue is a mosquito-borne disease called "break-bone fever," because it causes a high fever and such severe pain in the joints and bones that people who have it feel that their bones are breaking. It can take months to recover, may require hospitalization and kills 22,000 people each year, mostly children, according to the World Health Organization (WHO).
The WHO says the virus is now 30 times more prevalent than it was 50 years ago. It's common in many regions of Asia, the Pacific, the Americas and Africa. There are no particular drugs to fight dengue.
In addition to the vaccine, researchers are working on other ways to prevent or contain the virus. At the John's Hopkins mosquito lab, Professor George Demopoulos has discovered a way to block the dengue virus in lab mosquitos. The next step, he says, is to do the same in wild mosquitoes.
"Dengue and malaria are diseases that can only be controlled through the use of multiple approaches," he said. "It's like a war. You cannot win a war with only one weapon. You need multiple types of weapons and strategies to win a war. And the same applies for these diseases."
Other approaches include teaching people how to eliminate mosquito-breeding sites like water cisterns, water left in small containers near their homes or pools of standing water. Warmer climates and urbanization are increasing the spread of the mosquito that carries the virus. With urbanization, there's more standing water where mosquitoes can lay their eggs.
Dr. Luis Castellanos is an infectious disease expert with the Pan American Health Organization, or PAHO. The number of deaths from dengue
has declined in the Americas because, as he explains, "PAHO has extensively been working with the countries [of the Americas] over the last three, four years to train thousands of physicians throughout the countries to be ready to suspect dengue, identify, diagnose and treat any dengue case."
The World Health Organization estimates that 40 percent of the world's population is at risk for developing dengue. By this time next year, there may be a way to fight it.
