Pertussis Vaccine Testing for Freedom-from-toxicity.

The results of 9.5 years of official testing of vaccines containing pertussis vaccine, plain or adsorbed with alum, Al(OH)(3), or AlPO(4), are reported. Toxicity was evaluated by weight changes in mice at 3 and 7 days after injection and intercurrent deaths. Toxicity was encountered during the early use of AlPO(4) in pertussis vaccine products, with a special product and quadruple-antigen vaccines. Throughout the study Al(OH)(3) products, few in number, were the least reactive of the adsorbed products. The slopes of regression lines of graded-dose responses reflected variations in reactivity of "nontoxic" vaccines. The U.S.-prescribed test is discussed relative to the (i) reactivity in children, (ii) causes of toxicity, (iii) other assays for pertussis vaccine toxicity, and (iv) the use of a reference vaccine in the toxicity test.