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Do we need a booster of Hib vaccine after primary vaccination? A study on anti‐Hib seroprevalence in Sweden 5 and 15 years after the introduction of universal Hib vaccination related to notifications of invasive disease
Author(s) -
HALLANDER HANS O.,
LEPP TIIA,
LJUNGMAN MARGARETHA,
NETTERLID EVA,
ANDERSSON MIKAEL
Publication year - 2010
Publication title -
apmis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.909
H-Index - 88
eISSN - 1600-0463
pISSN - 0903-4641
DOI - 10.1111/j.1600-0463.2010.02674.x
Subject(s) - hib vaccine , medicine , vaccination , seroprevalence , pediatrics , confidence interval , tetanus , booster dose , haemophilus influenzae , immunology , immunization , antigen , antibody , serology , conjugate vaccine , biology , genetics , bacteria
Hallander HO, Lepp T, Ljungman M, Netterlid E, Andersson M. Do we need a booster of Hib vaccine after primary vaccination? A study on anti‐Hib seroprevalence in Sweden 5 and 15 years after the introduction of universal Hib vaccination related to notifications of invasive disease. APMIS 2010; 118: 878–87. The prevalence of IgG ELISA antibodies against Haemophilus influenzae polyribosyl ribitol phosphate (anti‐Hib) was studied in two Swedish seroepidemiologic materials. One study was performed in 1997 5 years after the introduction of universal Hib vaccination (N = 3320). Ten years later, a similar study was carried out to analyze the effect of vaccination on anti‐Hib prevalence (N = 2383). The median values of anti‐Hib concentrations (EU/mL) were almost identical in the two materials. The antigenic pressure including vaccination, natural infections and possible cross‐immunizations was thus assumed to be constant. The joint median was 0.50 EU/mL (95% confidence interval: 0.46, 0.56). However, there were also indications of reduced exposure to ‘Hib‐antigens’ over a 10‐year period. The proportion above the cut‐off point for protection, 0.15 EU/mL, decreased significantly for children aged 2–19 years from 78% in 1997 to 74% in 2007 (p = 0.034), and there was a significant increase in values below the minimal level of detection for adults from 17% in 1997 to 20% in 2007 (p = 0.009). In the 2007 material no specific age group could be identified with a lower immune profile than other age groups older than 3 years and there was a significant downward trend of invasive infections caused by Hib according to notification data for the period 1997–2008. Therefore, the conclusion is that presently there is no need for a booster dose of Hib vaccine in Sweden after primary vaccination but the situation should be carefully monitored.