Seroimmunity to diphtheria and tetanus among mother-infant pairs; the role of maternal immunity on infant immune response to diphtheria-tetanus vaccination.

Background: This study was designed to determine the levels of immunity against diphtheria and tetanus in 110 mothers with/without diphtheria-tetanus toxoid (dT) vaccination during pregnancy and their two-month-old infants before diphtheria-tetanus-pertussis (DTP) immunisation, and also to assess the influence of pre-vaccination passive immunity on the infants' immune response to three doses of DTP vaccination.

Subjects And Methods: Sera from 110 mother-infant pairs before DTP vaccination and from 69 infants after receipt of three doses of DTP vaccine were tested to measure antidiphtheria-antitetanus toxin IgG levels, using a commercial enzyme immunoassay. History of dT toxoid vaccination of mothers at pregnancy was recorded.