ANTIBODIES TO BORDETELLA-PERTUSSIS ADENYLATE-CYCLASE TOXIN IN NEONATAL AND MATERNAL SERA

To investigate the high prevalence among infants of antibodies to Bord etella pertussis adenylate cyclase toxin (ACT), cord-blood sera were e xamined for antibodies to ACT, filamentous hemagglutinin (FHA) and per tussis toxin (PT) using immunoblot analysis. Antibodies reactive with ACT were the most prevalent in neonatal sera. Similar reactivity of Ig G with ACT was found in each sample of a given neonatal-maternal pair, yet IgM reactive with ACT was virtually absent in neonatal sera, sugg esting that antibodies to ACT are maternally derived. Antibodies to AC T might come from infection or childhood vaccination of the mothers si nce pertussis vaccines from all US manufacturers elicited antibodies t o ACT in mice. Alternatively, these antibodies may have been elicited by a cross-reactive antigen such as Escherichia coli alpha-hemolysin, since all of the neonatal and maternal sera contained antibodies react ive with alpha-hemolysin.