This research will develop a mathematical model to understand the role of asymptomatic infections and protective immunity on the spread of Ebola virus. Based on their previous research the investigators have shown that 20-60% of people exposed to Ebola virus never develop clinical disease and remain asymptomatic. It is unclear if a person who is asymptomatically infected gains protective immunity against future exposure to the Ebola virus. If asymptomatic infections do offer protection, this could be extremely important in understanding and reducing the spread of Ebola virus. As part of the project, the investigators will develop and share easy-to-use, open access modeling tools that can be utilized by the public health policy and research community. The research team proposes five specific aims in modeling and understanding asymptomatic infections. They will design and study public health interventions that could leverage the effects of this protective immunity. One such strategy would include modeling a potential workforce comprised of caregivers who have been asymptomatically infected to establish a viral barrier similar to a ring vaccination strategy. They will characterize the implications of asymptomatic infections for vaccine trial design. They will utilize latent process models to determine if asymptomatic infections contributed to the scope and decline of previous Ebola epidemics, looking to see if there is a signature of asymptomatic immunity within an Ebola outbreak.