title: New data in a 200-year investigation.
authors.forename: Mike
authors.initials: M
authors.lastname: Bray
mesh_terms: D049672:History, 19th Century; D049673:History, 20th Century; D049674:History, 21st Century; D006801:Humans; D007111:Immunity, Cellular / Q000276:immunology; D007156:Immunologic Memory / Q000276:immunology*; D012900:Smallpox Vaccine / Q000008:administration & dosage / Q000266:history / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*; D013997:Time Factors; D014616:Vaccinia virus / Q000276:immunology*
chemical_list: D012900:Smallpox Vaccine