title: A sub-unit vaccine elicits IgG in serum, spleen cell cultures and bronchial washings and protects immunized animals against pneumonic plague.
abstract: In this study, the protection afforded against aerosolized Yersinia pestis by injection of an alhydrogel-adsorbed sub-unit vaccine has been compared with that given by an existing killed whole cell vaccine licensed for human use. The sub-unit vaccine protected mice against exposure to > 10(4) colony-forming units (c.f.u.) of virulent plague organisms (100 LD50 doses), whereas the whole cell vaccine provided only 50% protection against 1.8 x 10(3) c.f.u. In sub-unit vaccinees, IgG to each of the F1 and V antigens contained in the vaccine, was detected in serum, on direct secretion by spleen cells and in broncho-alveolar washings (BAL). In killed whole cell vaccinees, physiologically significant levels of IgG to F1 only were detectable in equivalent samples. Levels of F1-specific IgG in serum, secreted from spleen cells and in BAL were significantly higher (P < 0.01) in sub-unit compared with killed whole cell vaccinees. IgA was not detected in BAL from intra-muscularly dosed sub-unit vaccinees and thus the protection achieved against inhalational challenge with Yersinia pestis is attributed to the induction of systemic immunity to both the F1 and V antigens in the sub-unit vaccine. The enhanced protective efficacy of this sub-unit vaccine over an existing vaccine has been demonstrated in an animal model of pneumonic plague.
authors.affiliation: DERA (Chemical and Biological Defence Sector), Salisbury, Wiltshire, UK.
authors.forename: E D
authors.initials: ED
authors.lastname: Williamson
authors.forename: S M
authors.initials: SM
authors.lastname: Eley
authors.forename: A J
authors.initials: AJ
authors.lastname: Stagg
authors.forename: M
authors.initials: M
authors.lastname: Green
authors.forename: P
authors.initials: P
authors.lastname: Russell
authors.forename: R W
authors.initials: RW
authors.lastname: Titball
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis / Q000097:blood; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D001992:Bronchoalveolar Lavage Fluid / Q000276:immunology; D002478:Cells, Cultured; D004195:Disease Models, Animal; D005260:Female; D006801:Humans; D007114:Immunization; D007074:Immunoglobulin G / Q000096:biosynthesis* / Q000097:blood; D051379:Mice; D010930:Plague / Q000276:immunology / Q000517:prevention & control*; D010931:Plague Vaccine / Q000494:pharmacology*; D052899:Pore Forming Cytotoxic Proteins; D013154:Spleen / Q000276:immunology; D015164:Vaccines, Inactivated / Q000494:pharmacology; D014614:Vaccines, Synthetic / Q000494:pharmacology*; D015010:Yersinia pestis / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D007074:Immunoglobulin G; C043908:LcrV protein, Yersinia; D010931:Plague Vaccine; D052899:Pore Forming Cytotoxic Proteins; D015164:Vaccines, Inactivated; D014614:Vaccines, Synthetic; C086725:caf1 protein, Yersinia pestis