During a four-year surveillance of haemophilus infections in the Slovak Republic 7% of all cases of invasive cases in children occurred in children under the age of 3 months. 650 paired mother-neonate samples were examined with the objective to assess the anti PRP Hib antibody level. The mean level of PRP antibodies was 3.16 mg/l in mothers and 2.87 mg/l in neonates. The ratio of transmission of antibodies in individual paired sera was 17 - 98% (mean 91.7 %). 15 % of the neonate s had a level of anti PRP Hib antibodies lower than 0.5 mg/l. The authors found that 15 % neonates do not have at the age of 3 months a protective level of anti PRB Hib antibodies either due to low levels in the mother or due to inadequate transmission of antibodies from the mother.

        Key words: Haemophilus influenzae type b, antibodies, mother - neonates