BACKGROUND: Prematurity may be a risk factor for Haemophilus influenzae type b vaccine failure. This article evaluates the Haemophilus influenzae type b immunogenicity of a hexavalent diphtheria-tetanus-acellular pertussis-hepatitis B-inactivated poliovirus/Haemophilus influenzae type b vaccine in preterm infants (< 37 weeks' gestation). METHODS: This was an open-label, parallel group study. Preterm (N = 94) and term infants (N = 92) received 3 doses of a diphtheria-tetanus-acellular pertussis-hepatitis B-inactivated poliovirus/Haemophilus influenzae type b vaccine at 2, 4, and 6 months with a booster dose at 18 to 20 months. Antipolyribosyl ribitol phosphate antibody concentrations were determined in serum samples taken before and 1 month after primary and booster vaccination. RESULTS:Postprimary seroprotection rates (antipolyribosyl ribitol phosphate >; or = 0.15 microg/mL) were lower in preterm than in term infants (92.5% vs 97.8%), with antipolyribosyl ribitol phosphate geometric mean concentrations of 2.241 vs 4.247 microg/mL. A progressive reduction in immune response to the Haemophilus influenzae type b antigen was observed with decreasing length of gestation and decreasing birth weight when cutoff > or = 1 microg/mL was considered. Prebooster seroprotection rates and antipolyribosyl ribitol phosphategeometric mean concentrations were low in both groups (antipolyribosyl ribitol phosphate >; or = 1.0 microg/mL in 10.7% of preterm and 28.4% of term infants). A vigorous response to booster vaccination was seen in both groups, with no differences in postbooster seroprotection rates or antipolyribosyl ribitol phosphategeometric mean concentrations between the 2 groups (antipolyribosyl ribitol phosphate >; or = 1.0 microg/mL in 100% of preterm and 98.5% of term infants). CONCLUSIONS: Primary vaccination with a hexavalent diphtheria-tetanus-acellular pertussis-hepatitis B-inactivated poliovirus/Haemophilus influenzae type b vaccine at 2, 4, and 6 months with a booster dose at 18 to 20 months elicits a satisfactory antipolyribosyl ribitol phosphate response in preterm infants compared with term controls. Immunologic response decreased with decreased gestational age and birth weight.
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BACKGROUND: Prematurity may be a risk factor for Haemophilus influenzae type b vaccine failure. This article evaluates the Haemophilus influenzae type b immunogenicity of a hexavalent diphtheria-tetanus-acellular pertussis-hepatitis B-inactivated poliovirus/Haemophilus influenzae type b vaccine in preterm infants (< 37 weeks' gestation). METHODS: This was an open-label, parallel group study. Preterm (N = 94) and term infants (N = 92) received 3 doses of a diphtheria-tetanus-acellular pertussis-hepatitis B-inactivated poliovirus/Haemophilus influenzae type b vaccine at 2, 4, and 6 months with a booster dose at 18 to 20 months. Antipolyribosyl ribitol phosphate antibody concentrations were determined in serum samples taken before and 1 month after primary and booster vaccination. RESULTS: Postprimary seroprotection rates (antipolyribosyl ribitol phosphate > or = 0.15 microg/mL) were lower in preterm than in term infants (92.5% vs 97.8%), with antipolyribosyl ribitol phosphate geometric mean concentrations of 2.241 vs 4.247 microg/mL. A progressive reduction in immune response to the Haemophilus influenzae type b antigen was observed with decreasing length of gestation and decreasing birth weight when cutoff > or = 1 microg/mL was considered. Prebooster seroprotection rates and antipolyribosyl ribitol phosphate geometric mean concentrations were low in both groups (antipolyribosyl ribitol phosphate > or = 1.0 microg/mL in 10.7% of preterm and 28.4% of term infants). A vigorous response to booster vaccination was seen in both groups, with no differences in postbooster seroprotection rates or antipolyribosyl ribitol phosphate geometric mean concentrations between the 2 groups (antipolyribosyl ribitol phosphate > or = 1.0 microg/mL in 100% of preterm and 98.5% of term infants). CONCLUSIONS: Primary vaccination with a hexavalent diphtheria-tetanus-acellular pertussis-hepatitis B-inactivated poliovirus/Haemophilus influenzae type b vaccine at 2, 4, and 6 months with a booster dose at 18 to 20 months elicits a satisfactory antipolyribosyl ribitol phosphate response in preterm infants compared with term controls. Immunologic response decreased with decreased gestational age and birth weight.
Authors: E Chiappini; C Petrolini; C Caffarelli; M Calvani; F Cardinale; M Duse; A Licari; S Manti; A Martelli; D Minasi; M Miraglia Del Giudice; G B Pajno; C Pietrasanta; L Pugni; M A Tosca; F Mosca; G L Marseglia Journal: Ital J Pediatr Date: 2019-11-19 Impact factor: 2.638