Background: There are frequent concerns about early immunizations among the parents of children at heightened risk for atopy. The study assessed the effect of vaccine immunization before the first birthday on eczema severity and allergic sensitization in the second year of life.
Methods: A total of 2184 infants, aged 1-2 years, with established atopic dermatitis and a family history of allergy, from 97 study centres in 10 European countries, South Africa and Australia were included. Exposure to vaccines (diphtheria, tetanus, pertussis, polio, Haemophilus influenzae Type B, hepatitis B, mumps, measles, rubella, varicella, BCG, meningococci and pneumococci) and immunization dates were recorded from immunization cards. Immunoglobulin E (IgE) was determined by RAST and eczema severity was assessed by scoring atopic dermatitis (SCORAD).
Results: Immunization against any target was not associated with an increased risk of allergic sensitization to food or inhalant allergens. Varicella immunization (only 0.7% immunized) was inversely associated with total IgE > 30 kU/l (OR 0.27; 95% CI 0.08-0.87) and eczema severity (OR 0.34; 95% CI 0.12-0.93). Pertussis immunization (only 1.7% nonimmunized) was inversely associated with eczema severity (OR 0.30; 95% CI 0.10-0.89). Cumulative received vaccine doses were inversely associated with eczema severity (P = 0.0107). The immunization coverage of infants before and after the onset of atopic dermatitis was similar.
Conclusion: In children at heightened risk for atopy, common childhood immunization in the first year is not associated with an increased risk of more severe eczema or allergic sensitization. Parents of atopic children should be encouraged to fully immunize their children.