Serious challenges remain in dengue vaccine development

There are several dengue virus vaccine candidates in development, but interference caused by the mechanisms of a live dengue virus vaccine is delaying progress, according to data presented here. “Dengue has been a road on which there have been many obstacles,” Scott B. Halstead, MD, founder of the Pediatric Dengue Vaccine Initiative, said during a presentation. According to Halstead, approximately 4 billion people across 128 countries are at risk for infection with dengue virus, with 393 million infections and 96 million overt cases of dengue illness occurring in 2010. More severe forms of the disease carry a 5% mortality rate. Primary infection with a single dengue virus will provide lifetime homotypic immunity, but subsequent infection from the other three virus types are possible. Antibody responses to a primary infection are known to enhance disease caused by secondary infections. Halstead, somewhat tongue-in-cheek, characterized the severity of the disease in adults: “For 3 days you’re afraid...