Studies on Diphtheria. II. Immunization against diphtheria in newborn babies and in infants

Abstract

SUMMARYIn many countries nowadays the antitoxic immunity against diphtheria is most unsatisfactory. In Sweden less than 10 per cent of the non immunized adults have antibodies in »protective» concentrations. As a consequence the mothers but infrequently transfer to their offspring the passive immunity, which was formerly assumed to be the rule. Hence the question of immunization already at an early age becomes topic. Earlier authors almost unanimously expressed the view that an immunization during the first months of life is not practicable the infants at this age being considered to have a poor antitoxin producing power. The results of the experiments published in this paper clearly demonstrate that this opinion is erroneous. Even the newborns react upon diphtheria immunization with aluminium precipihted toxoid, although the response in antibody formation is often delayed. Earlier workers seem to have been misled by one or several of the following errors: the slow reaction of the newborns; the more or less complete interference of »passive» antibodies, exceeding 1/50–1/10 A. U./cc, with the active immunization; and the importance of even minute amounts of »active» antibodies, indicating former sensitization, for the results of immunization.