Repeated administration of whole-cell and acellular pertussis vaccines affects haemodynamics and autonomic...

Rats were treated in a repetitive way one to four times with either pertussis toxin, combined Diphtheria-Tetanus-Poliomyelitis-Pertussis vaccine (DTP-IPV vaccine, which includes inactivated polio virus and whole-cell pertussis), DT-IPV vaccine (lacking the whole-cell pertussis component) or acellular pertussis (aP) vaccine or Haemophilus influenzae type b vaccine. Baseline diastolic blood pressure, baseline heart rate and adrenergic and cholinergic responses were evaluated 4 days after last treatment. Pertussis toxin decreased baseline diastolic blood pressure (28-43%) and increased baseline heart rate (28-40%). Adrenergic and cholinergic response were inhibited by 65-75% and 70-78%. Multiple treatments were grossly as effective as single treatment. Similar results were obtained with DTP-IPV, while DT-IPV did not affect any of the four responses measured. Acellular pertussis vaccine did not affect baseline diastolic blood pressure, but significantly increased baseline heart rate (14%) and inhibited the adrenergic (19-23%) and cholinergic response (39-50%). This indicates that the acellular vaccine tested contains pharmacologically active pertussis toxin. As the effects were less pronounced compared to DTP-IPV, it is concluded that acellular pertussis retains less residual toxicological effects than whole-cell pertussis vaccine and may therefore be a safer vaccine. The observed effects on haemodynamics and autonomic control seem to be specific for pertussis toxin and pertussis-related vaccines as Haemophilus influenzae type b vaccine is in this respect virtually inactive.