Haemophilus influenzae serotype B (Hib) seroprevalence in England and Wales in 2009

• DOI: 10.2807/ese.17.46.20313-en
• Publication Date: 2017-10-04T10:03:00Z
• Authors: S N Ladhani; M E Ramsay; J S Flood; H Campbell; M P Slack; R Pebody; J Findlow; E Newton; M Wilding; R Warrington; H Crawford; S Y Min; K Gray; S Martin; S Frankland; N Bokuvha; G Laher; R Borrow
• Keywords: Seroprevalence; Carriage; Hib vaccine; Epiglottitis

A national seroprevalence study was performed to determine the prevalence of Haemophilus influenzae type b (Hib) antibodies in England and Wales 2009, when Hib disease incidence lowest ever recorded. total 2,693 anonymised residual sera from routine diagnostic testing submitted by participating National Health Service hospital laboratories were tested for anti-polyribosyl-ribitol phosphate (PRP) IgG using a fluorescent bead assay. Median anti-PRP concentrations highest toddlers aged 1–4 years (2.65 μg/ml), followed children 5–9 (1.95 μg/ml). Antibody significantly lower after this age, but still higher among 10–19 year-olds (0.54 μg/ml) compared with adults >20 (0.16 μg/ ml; p<0.0001). Half (51%) did not have antibody ≥0.15 μg/ml, level considered confer short-term protection. Thus, current excellent control appears be result high up 10 years, achieved through various childhood vaccination campaigns offering booster immunisation. The lack seroprotection emphasises importance maintaining and, most probably carriage, children, therefore raising question as whether long-term boosting either pre-school or adolescents may required.