Combined Haemophilus Influenzae Type B-Neisseria Meningitidis Serogroup C Vaccine Is Immunogenic and Well Tolerated in Preterm Infants When Coadministered With Other Routinely Recommended Vaccines

BACKGROUND:Preterm infants are at greater risk of morbidity from vaccine-preventable diseases. Therefore, their responses to vaccination are of particular interest. METHODS:In this open, controlled, Spanish multicenter study, we assessed immunogenicity and safety following primary vaccination of 163 preterm infants (n = 56, 36 weeksʼ gestation), with Haemophilus Influenzae type B (Hib)-MenC-TT, DTaP(diphtheria-tetanus-acellular pertussis vaccine)-HepB-IPV, and PCV7 at 2 to 4–6 months of age followed by booster vaccination at 16 to 18 months of age. Serum bactericidal activity (rabbit complement) against MenC, and antibodies to Hib and hepatitis b (anti-HBs) were determined. Local/general symptoms were assessed after each vaccination via diary cards. Serious adverse events were recorded throughout the study. RESULTS:There were no statistically significant differences between preterm and full-term infants in either Hib or MenC seroprotection rates or geometric mean concentrations at 1 month postdose 3, before or 1 month postbooster. Postdose 3, >99% of participants had seroprotective anti-HBs antibody concentrations. Anti-HBs geometric mean concentrations was significantly lower in the