Influence of dose and frequency of antigen injection on IgE development in young children: A comparison of fire ant stings and tetanus immunizations

Background: Previous studies suggest that small antigen doses given frequently are more likely to induce IgE production than are large antigen doses given infrequently. Objective: To compare the prevalence of antitetanus IgE resulting from the relatively large dose of tetanus toxoid delivered by standard immunizations at 2, 4, 6, and 18 months of age with the previously reported prevalence of anti-fire ant venom IgE resulting from the relatively small dose of venom delivered sporadically by accidental fire ant stings in children younger than 5 years. Methods: This study uses previously published data on the prevalence of IgE antibodies to imported fire ant venom among children living in an imported fire ant endemic area of Georgia and antitetanus IgE measurements of children recruited between August 1, 2003, and December 30, 2007, as part of the Wayne County Health, Environment, Allergy, and Asthma Longitudinal Study in Michigan, where there are no imported fire ants. The prevalence of anti-fire ant venom IgE antibodies was compared with the prevalence of antitetanus IgE antibodies in these 2 cohorts of children. Results: The reported prevalence of IgE to fire ant venom among 42 children 2 to 5 years old was 57.1% using a cutoff of 0.1 IU/mL and 35.7% using a cutoff of 0.35 IU/mL. The prevalence of antitetanus IgE in 395 children 2 years old was 52.9% using a cutoff of 0.1 IU/mL and 42.7% using a cutoff of 0.35 IU/mL. The proportion of children with detectable anti-fire ant venom IgE was not statistically significantly different from the proportion of those with antitetanus IgE at either cutoff level (P = .74 and .50 at 0.1 and 0.35 IU/mL, respectively). Conclusions: The relatively large dose of tetanus toxoid delivered 4 times during the first 24 months of life produces detectable tetanus specific IgE antibodies as frequently as the smaller doses of venom delivered sporadically by fire ant stings in young children.