کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
10964309 1102710 2014 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Evaluation and validation of a serum bactericidal antibody assay for Haemophilus influenzae type b and the threshold of protection
موضوعات مرتبط
علوم زیستی و بیوفناوری ایمنی شناسی و میکروب شناسی ایمونولوژی
پیش نمایش صفحه اول مقاله
Evaluation and validation of a serum bactericidal antibody assay for Haemophilus influenzae type b and the threshold of protection
چکیده انگلیسی
Prior to routine immunisation, Haemophilus influenzae serotype b (Hib) was a major cause of serious bacterial infections, particularly in young children. In the United Kingdom, introduction of the Hib conjugate vaccine into the national childhood immunisation schedule has led to a sustained decline in invasive Hib disease across all age-groups. Evaluation of the immune response to Hib conjugate vaccines involves measurement of serum IgG antibodies against the capsular polyribosyl-ribitol-phosphate (PRP) polysaccharide by enzyme-linked immunosorbent assay (ELISA), with accepted short-term and long-term protective thresholds of ≥0.15 μg/mL and ≥1.0 μg/mL, respectively. These levels were derived by passive immunisation or immunisation with pure polysaccharide, and their relevance for protection following immunisation with conjugate vaccines remains unclear. This study aimed to modify and optimise a serum bactericidal antibody (SBA) assay to evaluate the functional activity of Hib antibodies generated following Hib conjugate vaccination. Validation of the Hib SBA assay was deemed acceptable for all assay parameters tested. A strong correlation between anti-PRP IgG concentrations and SBA titres was observed in vaccinated adults (r = 0.81), as well as infants after primary immunisation at 2, 3, and 4 months (r = 0.635) and after the 12-month booster (r = 0.746). The assay identified some children with high anti-PRP IgG but low SBA activity and vice versa. The predictive protective SBA titre corresponding to a post-booster anti-PRP IgG of 1.0 μg/mL was 8. Thus, the optimised Hib SBA assay was specific and reproducible and correlated with anti-PRP IgG. Such assays may have a role in evaluating immune responses to conjugate vaccines in addition to measuring capsular antibodies.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Vaccine - Volume 32, Issue 43, 29 September 2014, Pages 5650-5656
نویسندگان
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