A mosquito-born disease, Dengue kills tens of thousands of people per year and sickens 100 million more. Known as "bone-break disease," Dengue is characterized by excruciating pain and was "the most important mosquito-borne viral disease affecting humans" in 2005 according to the U.S. Centers for Disease Control.
The study, from bioengineers and physicists at Rice University, appears in the March 24 issue of the journal Vaccine. The study suggests that the multi-site vaccination strategy, termed polytopic vaccination, may be effective against other diseases as well, including HIV and cancer.
Dengue infection occurs from one of four closely related viruses. Previous exposure to one of the four ?either by prior infection or by vaccination ?makes people significantly more likely to develop a potentially lethal hemorrhagic infection if they are later infected by one of the other three viruses.
"This is a classic case of something called 'original antigenic sin,' which happens when our immune system becomes overly reliant upon memory when recognizing diseases similar to those that it has seen before," said lead researcher Michael Deem, the John W. Cox Professor in Biochemical and Genetic Engineering and professor of physics and astronomy. "With diseases like HIV, influenza and Dengue, our acquired immune system's tendency to go-with-what-it-knows can leave us more vulnerable to infection from a mutant strain or a related virus. The immune system may respond less favorably in these cases than if it had never been exposed to the disease in the first place."
Original antigenic sin, or immunodominance, arises out of the procedure the immune system uses to target infection. This start