Michael Cotten, MD; Kathy J
Michael Cotten, MD; Kathy J. after the primary series, and had extra serum available. Subjects were also eligible if they completed a 2-dose primary series (at 2 and 4 months) of FMK PRP-OMP vaccine at one center (Rochester) able to draw blood samples 4C6 weeks thereafter. The primary outcome was geometric mean anti-PRP titer (GMT) 4C6 weeks following the primary Hib series (at 4 or 6 months of age). Anti-capsular PRP antibody was measured by the method of Phipps4 using PRP oligosaccharide (lower limit of detection = 0.10 g/mL). Of 244 infants in the primary study, 161 completed the secondary study. Birth weight was 1041 277 grams (mean standard deviation) and gestational age 28.0 2.0 weeks, with 68 infants FMK (42%) being 1000 grams. Infants were 6.3 0.4 months at conclusion of the primary series of vaccines, and 5.3 0.5 months and 7.4 0.5 months at blood draw for 2-dose PRP-OMP-only and 3-dose infants, respectively. Overall, 79% of infants had post-vaccination PRP titers 1.0 g/mL and 96% had titers 0.15 g/mL. PRP GMT were lower among infants 1000 Rabbit Polyclonal to OR10H2 grams birth weight (2.5 g/mL; [95% confidence interval: 1.7, 3.4]) than among those 1000 grams (3.6 g/mL; [2.7, 4.8]), but this difference did not reach statistical significance (p = 0.25) (Figure). Seventy-four percent of infants 1000 grams and 83% of infants 1000 grams achieved titers 1.0 g/mL (p = 0.15). Only 9 infants received a primary series of two doses of PRP-OMP vaccine, limiting the ability to draw conclusions about differing responses to differing vaccine types. Open in a separate window Figure Reverse distribution curve of antibody responsesInfants with birth weights 401C1000 grams (dashed line) and 1001C1500 grams (dash-dotted line) are shown. Solid vertical line denotes 1.0 g/mL and dashed vertical line denotes 0.15 /mL. FMK Curve allows an assessment of the proportion of children achieving various post-vaccination antibody levels. All infants with titers below the limit of detection were 1000 grams birth weight. The proportion of VLBW infants achieving the presumed long-term protective FMK PRP antibody titer of 1.0 g/mL is lower than the 90C95% reported for full term infants.5 Timely Hib vaccine boosting may be particularly important among VLBW infants. Supplementary Material Supplemental Digital Content _Including Separate Legend_Click here to view.(67K, doc) Acknowledgments The National Institutes of Health and the National Institute of Child Health and Human Development (NICHD) provided grant support for the Neonatal Research Networks PCV-7 Study. Data collected at participating sites of the NICHD Neonatal Research Network (NRN) were transmitted to RTI International, the data coordinating center (DCC) for the network, which stored, managed and analyzed the data for this study. On behalf of the NRN, Drs. Abhik Das (DCC Principal Investigator) and Lei Li (DCC Statistician) had full access to all the data in the study and take responsibility for the integrity of the data and accuracy of the data analysis. We are indebted to our medical and nursing colleagues and the infants and their parents who agreed to take part in this study. The following investigators, in addition to those listed as authors, participated in this study: NRN Chairs: Alan H. Jobe, MD PhD, University of Cincinnati (2001C2006); Michael S. Caplan, MD, Northwestern University (2006C2011). Duke FMK University Hospital, Alamance Regional Medical Center, and Durham Regional Hospital (M01 RR30, U10 HD40492) C C. Michael Cotten, MD; Kathy J. Auten, BS. Emory University(U10 HD27851, M01 RR39) C Ellen C. Hale, RN BS CCRC. National Institute of Child Health and Human Development C.