[Evaluation of residual immune response against human pox virus before and after revaccination in healthy volunteers].

Although the risk of smallpox virus being used as a terrorist weapon is very low, it is mandatory to examine potential vaccination strategies, and also the residual immunization rate in the general population. During revaccination of a national intervention team, the residual immunity of 184 volunteers was determined by assaying T memory cells in the gamma interferon ELISpot test, and central T memory cell responses in a proliferation assay. Three-quarters of the subjects had a proliferative response. This response was lower after the age of 55 years but could be reactivated by revaccination.