Researchers at the University of California, Berkeley, have identified a viral protein that causes fluid loss and shock that indicate severe and potentially fatal dengue infections. Dubbed nonstructural protein 1 (NS1), it is secreted by cells infected with the mosquito-borne virus. It causes the endothelium of blood and lymph vessels to become permeable, which can lead to blood vessels that leak fluid. The researchers say that NS1 could be a prime target for drugs and should be considered in vaccine development. More