A major route toward creating effective vaccines against dengue virus and Zika involves the E protein that covers the surface of each viral particle. If we could develop strong antibodies against this E protein, then that would be the crux of a formidable vaccine—based on the important fact that the 180 E proteins come in pairs. But creating such a vaccine has proven difficult for a number of reasons. Now UNC School of Medicine researchers have delineated the details of one major barrier to a promising vaccine. It’s something we all have—a natural body temperature of about 98.6 degrees.