Vaccination against Haemophilus influenzae type b and atopy in East German schoolchildren

Introduction: Although routine childhood immunisations are known to prevent severe diseases there is an ongoing discussion on possible side effects in later life. In this paper we investigated the association of Haemophilus influenzae type b (Hib)-vaccination and atopic diseases and allergic sensitisation in children in Eastern Germany. Methods: From 1998-1999 a cross-sectional survey of school children aged 5 to 14 years on long-term health effects of air pollution was conducted in three regions of Eastern Germany. Atopic outcome was defined by parental reporting of wheezing and doctor's diagnosed asthma (including asthma-like bronchitis), hay fever and eczema. Specific serum IgE against 5 aeroallergens were analysed by RAST-technique. Vaccination status was assessed by vaccination records from the respective local health authorities. Analysis is restricted to 1943 children with complete information on age, gender, place of residence, parental education and 1676 children with available blood data. Results: Lifetime prevalence were 4.9% for asthma, 21.1% for wheezing, 6.6% for hay fever, 11.4% for eczema. 32% of the children had at least one specific IgE RAST > 0. Hib-vaccination coverage was 42% overall, 93% In 5-7 yr olds, 59% in 8-10 yr olds and 11% in 11-14 yr olds. Odds Ratios adjusted for age, gender, place of residence, and parental education were 1.86 [1.05-3.32] for asthma, 1.55 [0.95-2.54] for hay fever, 1.03[0.70-1.50] for eczema and 1.25 [0.94-1.67] for at least I specific IgE RAST > 0. Conclusion: We found little evidence for an association between Hib-vaccination and some atopic outcomes and causality cannot be ascertained. Our findings do not give sufficient support to question the value of Hib vaccination given the substantial contribution of mass immunisations to public health. Specific research on possible long-term effects of vaccines is needed to enable final conclusions on this topic.