Pertussis seroimmunity in mother-neonate pairs and other pediatric age groups from Egypt

Background: Despite the widespread availability of 2 classes of effective vaccines, whole cell and acellular, pertussis has resurged as a serious public health problem. We sought to investigate the pertussis immune status of mother-neonate pairs and children in our country where pertussis vaccination is obligatory. Methods: This cross-sectional study included 75 healthy full-term neonates and their mothers, 100 infants (2-24 months), 170 children (2-12 years) and 80 adolescents (12-18 years). Serum pertussis IgG was measured in all enrolled subjects. A positive titre was defined as >24 U/ml. Results: Positive pertussis IgG levels were detected in 69 of the mothers (92%), in 63 of their newborns (84%). Seroimmunity to pertussis was positively noted in 55% of infants, 82.2% of preschool children, 77.5% of school-aged children and 75% in adolescents. Serum pertussis IgG titers among the neonates showed a significant positive correlation with the maternal titers (P=0.00001). Higher rates of pertussis seroimmunity was observed among residents in urban and suburban areas as compared to those living in rural areas (P<0.05) . Conclusion: This pilot study may suggest the presence of sufficient pertussis seroimmunity rates in the studied age groups. Still, there were some failures in immune acquisition probably due to inefficient vaccination in some localities or waning of immunity with age. Wider scale studies would allow better insight into the pertussis immune status in our country and hence the need for booster immunization