Immunologic Response toHaemophilus influenzaeType b (Hib) Conjugate Vaccine and Risk Factors for Carriage among Hib Carriers and Noncarriers in Southwestern Alaska

Abstract

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 g/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.

Serum IgM Antibodies Contribute to High Levels of Opsonophagocytic Activities in Toddlers Immunized with a Single Dose of the 9-Valent Pneumococcal Conjugate Vaccine

“…There are also two studies that have described an association of IgM with functional antibody activity against Hib in older children and adults (2,9).…”

The effect of rituximab on vaccine responses in patients with immune thrombocytopenia

“…18 For the test, twofold serial dilutions of test sera were incubated with 10 000 bacterial cells per well of Hib (strain GB3292) with 10 mL of Hanks buffer with Ca 21 and Mg 21 (Life Technologies), 2% Fildes enrichment (BBL; Becton Dickinson and Co.), and complement (sterile serum from 3-to 4-week-old baby rabbits; Pel-Freez). Bactericidal activity was assessed using Alamarblue, a fluorescent metabolic indicator (Life Technologies).…”

Anticapsular Polysaccharide IgG Concentrations in Mexican Children Formerly Immunized with Haemophilus Influenzae b Prp-T Vaccine

“…14,[29][30][31][32][33][34] According to their multi-ethnic origin, the children of Mexico could also depict variations regarding susceptibility to Hib disease and/or colonization. Although the GMCs of the 13-24 (1.6 mg/mL) and 25-48 (1.4 mg/mL) month-old groups were almost three-times lower than those observed for the less than one-year olds, these groups are likely to be protected against disease.…”