RT Journal Article SR Electronic T1 Immunologic Response of Extremely Premature Infants to Tetanus, Haemophilus influenzae, and Polio Immunizations JF Pediatrics JO Pediatrics FD American Academy of Pediatrics SP 18 OP 22 VO 96 IS 1 A1 D'Angio, Carl T. A1 Maniscalco, William M. A1 Pichichero, Michael E. YR 1995 UL http://pediatrics.aappublications.org/content/96/1/18.abstract AB Objective. To determine whether extremely premature infants have immunologic responses to tetanus toxoid, Haemophilus influenzae type b polysaccharide and polio vaccines similar to those of full-term infants. Infants and Methods. Sixteen extremely premature (<29 weeks, <1000 g at birth) infants received separate diphtheria-tetanus-pertussis and H influenzae type b oligosaccharide-CRM,197-conjugated (HbOC) vaccines at 2, 4 and 6 months of chronologic age, enhanced potency inactivated polio vaccine at 2 months, and oral polio vaccine at 4 months. Serum was obtained for anti-tetanus toxoid (TT), anti-Haemophilus b polysaccharide (HbPs) and polio neutralizing antibody assays before the 2-month vaccination and 4 to 6 weeks after the 6-month vaccination. Comparison sera were obtained from full-term infants immunized with the same lots of diphtheria-tetanus-pertussis (n = 46) and HbOC (n 66) vaccines or the same sequence of polio vaccines (n = 10). Results. Preterm and full-term infants had similar geometric mean titers of anti-TT antibodies, anti-HbPs antibodies, and neutralizing antibodies to polio serotypes 1, 2, and 3 after the completion of the primary series of vaccines. After vaccination, similar proportions of preterm and full-term infants had protective levels of antibody to TT (preterm 100% vs full-term 100% with levels >0.01 IU/mL), HbPS (82% vs 87%, >1.0 µg/mL), and polio serotypes 1 (85% vs 80%, ≥1:8) and 2 (100% vs 100%, ≥1:8). Preterm infants were less likely than full-term infants to have protective levels of neutralizing antibody to polio serotype 3 (31% vs 90%, ≥1:8). Conclusions. Extremely premature infants have adequate antibody responses to tetanus and HbOC antigens but may have diminished responsiveness to serotype 3 polio vaccine.