A Long-Term Study of Healthy Adults Vaccinated With One Dose of Smallpox Vaccine (LISTER Strain)

None of the participants in this study will receive any vaccination as part of the study. All participants will provide blood samples for immunogenicity testing at the 1, 2, 3, 4, and 5 year anniversaries of vaccination. Safety will be assessed for up to 5 years after vaccination, including follow-up of reactions that occurred during Study VVL04 (NCT 00258947).