RESPONSES TO ACELLULAR PERTUSSIS VACCINES AND COMPONENT ANTIGENS IN ACOUGHING-RAT MODEL OF PERTUSSIS

Two acellular pertussis vaccines (SmithKline Beecham 3-component and C onnaught 5-component), and a whole-cell pertussis vaccine (Evans), wer e similarly protective against paroxysmal coughing and leukocytosis in a coughing-mt model of pertussis. A two-dose immunization schedule wa s followed by sublethal intrabronchial challenge with Bordetella pertu ssis strain 18-323, encased in fine agarose beads, and the coughing mo nitored by sound-activated tape recorders. Pertussis toroid by itself gave some protection against coughing, but lower than that afforded by the vaccines, despite inducing a higher serum anti-PT titre. The othe r component antigens, given individually, failed to prefect against co ughing although inducing antibodies. Immunization with the whole-cell and acellular vaccines and with their component antigens, as well as c hallenge with B. pertussis, caused significant elevation of total seru m IgE antibodies. Antigen-specific IgG and IgA were detected in trache obronchial washings from rats recovering from B. pertussis challenge, but vaccination prior to challenge had little influence on these antib ody levels. The coughing-rat model of pertussis may be useful for the comparative testing of different formulations of pertussis vaccines be fore trials in human infants. (C) 1998 Elsevier Science Ltd. All right s reserved.