[Immunologic transformation against pertussis in children following a second revaccination with ADPT-vaccine].

Immunological reconstruction was studied in children aged 6 years after the second revaccination with absorbed, pertussis-diphtheria-tetanus vaccine (APDT) in a strictly controlled trial. Antipertussis protective antibodies were determined in the sera in the passive hemagglutination test and the antigen neutralization test, whose results were characterized by the following regularities: the average (1:160--1:640) and the high (1:1280 and over) antibody titres were recorded 1 to 1.5 months after the vaccination in 46.9--48.9% of the persons vaccinated. Determination of the changes of the immunoglobulins A, M, and G at various periods after the second revaccination demonstrated that 1 to 1.5 months after the revaccination (that is at the peak of the antipertussis antibodies formation) 55.7--50.0% of the children displayed an elevation of the IgA and IgM against the background of the IgG reduction in 69.7% of cases.