A sub-unit vaccine elicits IgG in serum, spleen cell cultures and bronchial washings and protects immunized animals against pneumonic plague

• Published in: Vaccine 1997-07, Vol.15 (10), p.1079-1084
• Main Authors: Diane Williamson, E., Eley, Steven M., Stagg, Anthony J., Green, Michael, Russell, Paul, Titball, Richard W.
• Format: Article
• Language: English
• Subjects: Animals; Antibodies, Bacterial - biosynthesis; Antibodies, Bacterial - blood; Antigens, Bacterial; Bacterial Proteins; Bacteriology; Biological and medical sciences; Bronchoalveolar Lavage Fluid - immunology; Cells, Cultured; Disease Models, Animal; Female; Fundamental and applied biological sciences. Psychology; Humans; Immunization; Immunoglobulin G - biosynthesis; Immunoglobulin G - blood; immunological correlates; Mice; Microbiology; Plague - immunology; Plague - prevention & control; Plague Vaccine - pharmacology; pneumonic plague; Pore Forming Cytotoxic Proteins; protection; Spleen - immunology; sub-unit vaccine; Vaccines, antisera, therapeutical immunoglobulins and monoclonal antibodies; Vaccines, Inactivated - pharmacology; Vaccines, Synthetic - pharmacology; Yersinia pestis; Yersinia pestis - immunology
• ISSN: 0264-410X; 1873-2518
• DOI: 10.1016/S0264-410X(96)00303-9

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 > 104 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 × 103 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.