Immunologic response to Haemophilus influenzae type b (Hib) conjugate vaccine and risk factors for carriage among Hib carriers and noncarriers in Southwestern Alaska.
Continued Haemophilus influenzae type b (Hib) carriage in rural Alaska contributes to the ongoing risk of invasive disease. Community-wide Hib carriage surveys were conducted in three villages in southwestern Alaska. Sixteen carriers and 32 age- and village-matched controls were enrolled and were vaccinated with Hib oligosaccharide-CRM(197) conjugate vaccine. Serum immunoglobulin G (IgG) concentration, antibody avidity, and serum bactericidal activity (SBA) were measured prior to Hib vaccination and 2 and 12 months after vaccination. We identified no demographic or behavioral factors associated with Hib colonization. Prior to vaccination, Hib carriers had a higher IgG geometric mean concentration than controls did (8.2 versus 1.6 microg/ml; P < 0.001) and a higher SBA geometric mean titer (7,132 versus 1,235; P = 0.006). Both groups responded to vaccination with increased IgG and SBA. These data illustrate the role of Hib colonization as an immunizing event and show that Hib carriers in communities with ongoing transmission have no evidence of reduced immune responsiveness that may have put them at risk for colonization.
Baggett
Henry C
HC
CDC, Division of Global Migration and Quarantine, MS E03, 1600 Clifton Rd., Atlanta, GA 30333, USA. hbaggett@cdc.gov
Hennessy
Thomas W
TW
Bulkow
Lisa
L
Romero-Steiner
Sandra
S
Hurlburt
Debra
D
Holder
Patricia
P
Parkinson
Alan J
AJ
Singleton
Rosalyn J
RJ
Levine
Orin
O
Carlone
George M
GM
Butler
Jay C
JC
D000293:Adolescent; D000328:Adult; D000413:Alaska / Q000453:epidemiology; D000907:Antibodies, Bacterial / Q000097:blood; D000915:Antibody Affinity / Q000502:physiology; D001428:Bacterial Vaccines / Q000008:administration & dosage; D002353:Carrier State / Q000453:epidemiology* / Q000208:ethnology / Q000517:prevention & control; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006192:Haemophilus Infections / Q000453:epidemiology* / Q000517:prevention & control; D018073:Haemophilus Vaccines / Q000276:immunology*; D019741:Haemophilus influenzae type b / Q000737:chemistry*; D006801:Humans; D008297:Male; D012307:Risk Factors; D012424:Rural Population; D013997:Time Factors; D018074:Vaccines, Conjugate / Q000276:immunology
D000907:Antibodies, Bacterial; D001428:Bacterial Vaccines; D018073:Haemophilus Vaccines; D018074:Vaccines, Conjugate