We found a matchYour institution may have access to this item. Find your institution then sign in to continue.TitleDuration of antiviral immunity after smallpox vaccination.AuthorsHammarlund E; Lewis MW; Hansen SG; Strelow LI; Nelson JA; Sexton GJ; Hanifin JM; Slifka MKPublicationNature medicine, 2003, Vol 9, Issue 9, p1131ISSN1078-8956Publication typearticleDOI10.1038/nm917