Systems Serology aims to define the features of the humoral immune response against a given pathogen. Systems Serology analysis includes measurement of the levels antigen-specific antibodies within individual patients, measurement of antibody-mediated induction of innate immune cell effector functions, measurement of binding of antigen-specific antibodies to Fc-receptors, and measurement of neutralizing activity. Samples are taken from Ebola or Lassa Fever patients, convalescent survivors, or household contacts of these patients in Sierra Leone.