CIAO3 and diphtheria: A strong correlation between maternal and cord serum antibody levels was found for anti-diphtheria (Dtx) (R2 = 0.8920), anti-tetanus (Ttx) (R2 = 0.9062), anti-pertussis toxin (Ptx) (R2 = 0.6874), anti-pertactin (Prn) (R2 = 0.8867), anti-measles (R2 = 0.8908), anti-mumps (R2 = 0.6113) and anti-rubella (R2 = 0.5569).