Dm. Waag et al., IMMUNOGENICITY OF A NEW LOT OF FRANCISELLA-TULARENSIS LIVE VACCINE STRAIN IN HUMAN VOLUNTEERS, FEMS immunology and medical microbiology, 13(3), 1996, pp. 205-209
A new lot of Francisella tularensis live vaccine strain (LVS) was test
ed for immunogenicity in 19 human volunteers, Scarification vaccinatio
n induced specific cell-mediated and humoral immune responses, We note
d a significant rise in antibodies against irradiation-killed LVS, for
malin-killed virulent strain SCHU4, and an ether extracted antigen pre
paration (EEx) beginning 14 days after vaccination. A main target of t
he humoral immune response was lipopolysaccharide. Eighty percent of v
accinated volunteers developed a positive Ige response to EEx by day 1
4 and 100% of vaccinees responded positively by day 21, Background IgA
titers were lower than corresponding IgG or IgM titers, No early IgM
rise was noted with any antigen, By day 14 after vaccination, in vitro
lymphocyte responses to LVS,the rough variant of LVS, and EEx were si
gnificantly increased compared to controls, Seventy percent of volunte
ers had a positive in vitro lymphocyte response to EEx within 14 days
of vaccination, We predict that EEx will be a useful antigen or diagno
sing tularemia and for evaluating the immunogenicity of vaccines again
st tularemia. We are testing this antigen using sera from human cases
of tularemia and control sera.