Antibody levels against B. pertussis in neonates measured in dried blood spots

► Whooping cough is a contagious disease with a rising incidence ► Collection of small blood samples in small children on filter paper (Guthrie card) is feasible and less invasive than venous puncture. ► Our results show that maternal IgG-PT levels against B. pertussis measured in cord blood applied to Guthrie cards and calibrated against blood spot calibrators show good agreement with IgG-PT levels in cord serum. ► This offers practical tools for future studies concerning B. pertussis antibodies especially in young children.