FS02.7 Rates of persistent itchy nodules after fourth dose of DT vaccines

Abstract

Background: Studies in Gothenburg, Sweden, reported unexpectedly high rates, 0.35–1.66%, of late occurring itching nodules at the site of injection of aluminium containing vaccines. Among 455 children with itching nodules after vaccination, 352 had a positive epicutaneous test to aluminium. When switching to a new booster diphtheria‐tetanus vaccine in Sweden these findings warranted a comparative study of local itching nodules that had remained at least 2 months after injection, and of aluminium contact allergy.Methods: A prospective cluster randomised study was done in 25,232 10‐year‐olds. Participating schools in each municipality were randomised in a 1/1 ratio to use the old diphtheria‐tetanus toxoid (DT) vaccines, Duplex® or the new vaccine, diTeBooster®. Parental reports 6 months after vaccination were obtained for 22,365 (88%) pupils in 851 schools. Patch testing with aluminium chloride‐hexahydrate was performed in 9 children with an itching nodule, 6 children only pruritus and 17 children without any itching nodule after the fourth dose of DT vaccine.Results: We identified 3–6 children per 10000 with a local itching nodule persisting for at least 2 months. There were no significant differences between the vaccine groups. Contact allergy to aluminium was not detected.Conclusion: Our findings support the use of the vaccine presently available in the Swedish vaccination program. Continued surveillance of persistent itching nodules after vaccination with different aluminium containing DT and diphtheria‐tetanus‐pertussis toxoid (DTP) vaccines is however warranted.