Childhood immunization ‘not linked to asthma in adulthood’
MedWire News: Childhood immunization against smallpox, diphtheria, and other diseases is not associated with an increased risk for asthma and allergies in middle-age, research shows.
Writing in the journal Pediatric Allergy and Immunology, Melanie Matheson (University of Melbourne, Victoria, Australia) and team say their findings should reassure doctors and parents of the safety of these immunizations, after conflicting data for and against a potential association were reported.
Most of these studies involved children and young adults, and possible associations between childhood immunizations and such diseases in middle-aged adults had not previously been investigated.
To address this, the researchers assessed data from the Tasmanian Longitudinal Health Study on 5729 participants who were followed-up from the age of 7 to 44 years.
Most of the participants (up to 90.7%) had undergone childhood immunization against diphtheria, tetanus, pertussis, polio, and/or smallpox.
By the age of 44 years, 11.2% of the participants had been diagnosed with asthma, 11.1% had at least one food allergy, 37.0% had eczema, and 50.3% had hayfever.
After accounting for confounders, multivariable regression analysis revealed no significant associations between any childhood immunization and asthma (odds ratios [ORs] ranging from 0.87 to 1.17), eczema (ORs=0.99–1.07), food allergy (ORs=0.97–1.11), and hayfever (ORs=1.02–1.05) at age 44 years.
Cox regression analysis also revealed no significant associations between any childhood immunization and incident asthma after the age of 7 years (ORs=1.03–1.21).
Matheson and team conclude: “Our study does not support an association between childhood immunizations and atopic diseases, nor asthma incidence into middle-age.
“Our results should, therefore, reassure parents that immunization is a safe and important measure to protect their children against potentially life threatening illnesses.”
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By Mark Cowen