Pharmacological evaluation of purified component and whole-cell pertussis vaccine in the cardiovascular system of rats.

The present study compares the cardiovascular activity of a newly introduced and possibly safer acellular pertussis vaccine with that of a conventional whole-cell pertussis vaccine. The vasodilation that occurs after beta-2 adrenoceptor stimulation with salbutamol, as well as the negative chronotropic action induced by the muscarinic receptor stimulant arecoline, were inhibited 4 days after vaccination with two combined diphtheria-pertussis-tetanus whole-cell vaccines and their plain pertussis product. Using doses equivalent to those given to humans, detoxified acellular pertussis component-combined vaccines (diphtheria-pertussis-tetanus) and the nonabsorbed (detoxified pertussis component) induced minimal or no reduction in vascular beta-2 adrenergic and cardiac cholinergic receptor responsiveness as compared to saline-treated animals. Moreover, basal blood pressure values were significantly lower in whole-cell vaccine-treated rats than in animals vaccinated 4 days previously with acellular vaccine (or its ground products). Assuming that the present model can be used to predict the toxicity of pertussis vaccines in infants, it is concluded that the absence of a strong autonomic impairment might point toward the use of a less toxic acellular component vaccine in clinical practice.