An experimental vaccine to prevent Ebola virus disease was well-tolerated and produced immune system responses in all 20 healthy adults who received it in a Phase 1 clinical trial conducted by researchers from the National Institutes of Health. The candidate vaccine, which was co-developed by the NIH's National Institute of Allergy and Infectious Diseases (NIAID) and GlaxoSmithKline (GSK), was tested at the NIH Clinical Center in Bethesda, Maryland. The interim results are reported online in advance of print in the New England Journal of Medicine.