Heptavalent pneumococcal conjugate vaccine immunogenicity in very-low-birth-weight, premature infants.
BACKGROUND
The heptavalent pneumococcal CRM197 conjugate vaccine (PCV-7) has been incompletely studied in very-low-birth-weight (< or =1500 g) infants.


OBJECTIVE
To assess PCV-7 immunogenicity in very-low-birth-weight, premature infants. We hypothesized that the frequency of postvaccine antibody concentrations > or =0.15 microg/mL would vary directly with birth weight.


METHODS
This was a multicenter observational study. Infants 401 to 1500 g birth weight and <32 0/7 weeks gestation, stratified by birth weight, were enrolled from 9 National Institute of Child Health and Human Development Neonatal Research Network centers. Infants received PCV-7 at 2, 4, and 6 months after birth and had blood drawn 4 to 6 weeks following the third dose. Antibodies against the 7 vaccine serotypes were measured by enzyme-linked immunosorbent assay.


RESULTS
Of 369 enrolled infants, 244 completed their primary vaccine series by 8 months and had serum obtained. Subjects were 27.8 +/- 2.2 (mean +/- standard deviation) weeks gestation and 1008 +/- 282 g birth weight. Twenty-six percent had bronchopulmonary dysplasia and 16% had received postnatal glucocorticoids. Infants 1001 to 1500 g birth weight were more likely than those 401 to 1000 g to achieve antibody concentrations > or =0.15 microg/mL against the least 2 immunogenic serotypes (6B: 96% vs. 85%, P = 0.003 and 23F: 97% vs. 88%, P = 0.009). In multiple logistic regression analysis, lower birth weight, postnatal glucocorticoid use, lower weight at blood draw, and Caucasian race were each independently associated with antibody concentrations <0.35 microg/mL against serotypes 6B and/or 23F.


CONCLUSIONS
When compared with larger premature infants, infants weighing < or =1000 g at birth have similar antibody responses to most, but not all, PCV-7 vaccine serotypes.
University of Rochester School of Medicine and Dentistry, Rochester, NY, USA. carl_dangio@urmc.rochester.edu
Carl T
CT
D'Angio
Roy J
RJ
Heyne
T Michael
TM
O'Shea
Robert L
RL
Schelonka
Seetha
S
Shankaran
Shahnaz
S
Duara
Ronald N
RN
Goldberg
Barbara J
BJ
Stoll
Krisa P
KP
Van Meurs
Betty R
BR
Vohr
Abhik
A
Das
Lei
L
Li
Robert L
RL
Burton
Betty
B
Hastings
Dale L
DL
Phelps
Pablo J
PJ
Sanchez
Waldemar A
WA
Carlo
David K
DK
Stevenson
Rosemary D
RD
Higgins
D000907:Antibodies, Bacterial / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D019102:Infant, Very Low Birth Weight; D022242:Pneumococcal Vaccines / Q000008:administration & dosage / Q000276:immunology*; D014481:United States
D000907:Antibodies, Bacterial; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D022242:Pneumococcal Vaccines