The effect of aluminium phosphate adjuvant on the potency of pertussis vaccine

Abstract

Most whole cell pertussis vaccines are combined with diphtheria and tetanus toxoids and are adsorbed on to an adjuvant such as aluminium hydroxide, aluminium phosphate or calcium phosphate. ‘~4 The effect of the adjuvant on the potency has always been a matter of controversys-’ ’ but Preston et al. 12-‘* advocated that the need to incorporate the adjuvant in pertussis vaccine was beyond question. The mouse potency test for pertussis vaccine developed by Kendrick et al. l5 is the only model available that provides a laboratory measure of vaccine potency which, as in the British Field Trials, l6 has been correlated with clinical efficacy. In this paper, the effect of aluminium phosphate adjuvant on the mouse potency of pertussis vaccine is described. Two batches of pertussis suspensions from each of the five types of pertussis vaccine, i.e. heat inactivated pertussis vaccine (HIPV), formaldehyde inactivated pertussis vaccine (FIPV), glutaraldehyde inactivated pertussis vaccine (GIPV), thimerosal inactivated pertussis vaccine (TIPV) and acetone (I) treated pertussis vaccine (A(I)TPV), were prepared as described elsewhere. “.18 Each suspension contained organisms from Bordetellapertussis strains 134 and 509 in equal proportions, and each of the ten batches was diluted in normal saline (thimerosal O-0 1%) to contain 4 X IO”’ organisms/ml. Each batch of the plain pertussis vaccine, thus prepared, was tested for potency.