Background: Wild-type varicella zoster infection (WTVZV) up to 8 yr of age has been shown to protect against atopic dermatitis (AD) and asthma. We sought to determine whether WTVZV in childhood protects against atopic disorders, allergic sensitization or decreases serum Immunoglobulin E (IgE) levels.
Methods: We conducted a retrospective, practice-based study of outpatient pediatric practices in NY. One hundred children with WTVZV up to 8 yr of age and 323 children who received varicella vaccine (VV) were randomly selected.
Results: WTVZV up to 8 yr of age is associated with decreased odds of subsequent asthma (exact logistic regression; OR = 0.12, 95% CI = 0.03-0.57, p = 0.003), allergic rhinoconjunctivitis (OR = 0.16, 95% CI = 0.05-0.49, p = 0.0003), and AD (OR = 0.57, 95% CI = 0.33-0.96, p = 0.02), but not food allergies (p = 0.78); decreased total serum IgE levels [mixed linear model, LSM (95% CI): 129.09 (33.22-501.63) vs. 334.21 (102.38-1091.04) IU/ml; p = 0.02] remained significant at all time intervals after WTVZV (<5, 5-10, and >10) compared with VV (p = 0.003-0.03). WTVZV was associated with decreased allergic sensitization (logistic regression, OR = 0.11, 95% CI = 0.03-0.38, p = 0.0004). WTVZV is also associated with persistently decreased numbers of peripheral blood lymphocytes (p < 0.0001) for up to 12 yr (p = 0.0003-0.047), monocytes (p = 0.002) for up to 16 yr (p < 0.001) and basophils at ages 4-6, 10-12, and 14-16 (p < 0.03).
Conclusion: WTVZV up to 8 yr of age protects against atopic disorders, which is likely mediated by suppression of IgE production and allergic sensitization, as well as altered leukocyte distributions.
© 2011 John Wiley & Sons A/S.