A new study conducted at Rice University in Texas has shown that a new vaccination technique can help protect against the four known varieties of the dengue viruses. Particularly virulent in Africa, dengue is a mosquito-borne disease that kills tens of thousands of people every year and infects 100 million others. The study results also suggested that a multisite vaccination strategy -- "polytopic" vaccination -- might also be effective against other diseases, 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 much more likely to develop a potentially fatal hemorrhagic infection if they are infected later by one of the other three viruses.