Serological response to filamentous hemagglutinin and lymphocytosis-promoting toxin of Bordetella pertussis.

Serum antibody responses to the filamentous hemagglutinin and the lymphocytosis-promoting toxin of Bordetella pertussis after vaccination with diphtheria and tetanus toxoids and pertussis vaccine, adsorbed, were assayed by using the enzyme-linked immunosorbent assay. The effect of early immunization, during the first week of life, on the antibody response also was determined. After vaccination, immunoglobulin G (IgG) and IgM directed against both the filamentous hemagglutinin and the lymphocytosis-promoting toxin were detected. Generally, antibody titers increased with subsequent injections and the age of the children. Maternal antibodies against filamentous hemagglutinin and lymphocytosis-promoting toxin were detected in cord blood. The ability of an infant to produce serum IgG anti-lymphocytosis-promoting toxin after vaccination with pertussis vaccine was inversely related to the cord blood serum IgG anti-lymphocytosis-promoting toxin titer at birth. A good antibody response was observed in infants with low cord blood titers, and a poor antibody response was seen in infants with high cord blood values. The IgM anti-lymphocytosis-promoting toxin response was good in groups with both low and high cord blood titer, with no significant difference observed between the two groups. No IgA anti-lymphocytosis-promoting toxin or IgA anti-filamentous hemagglutinin titers were observed in vaccines. IgA antibodies were observed in convalescent sera from two adults and may be presumptive evidence of infection with B. pertussis.