Significance of the Loss of Potency in the Pertussis Component of Certain Lots of Quadruple Antigen

THE use of combined immunization with multiple antigens in a single mixture has been greatly expanded during the past fifteen years, because the advantages of such combinations were tremendous and the problems resulting from their use have been minor. The most recent such combination to become widely used has been a diphtheria-pertussis-tetanuspoliomyelitis combination or "quadruple antigen." Batson et al.1 first reported on the use of inactivated poliovirus vaccine mixed in the syringe with antigens for diphtheria, pertussis and tetanus (DPT), and soon afterward Barrett and his colleagues2 described the same combination mixed at the producing laboratory. Both reports furnished data . . .