Impact of Vaccination on Th2 Immunity in Infancy

Study Overview
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Brief Summary
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The purpose of this study is to assess the responses in the immune system of infants after they receive the vaccine against diphtheria, tetanus, and pertussis (DTaP). The investigators will do this by studying the immune cells and allergy responses in the blood prior to and after receipt of the third DTaP vaccine.

Detailed Description
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This is a single-site study of infants who are scheduled to receive their third series ( 6 month) vaccinations, as routine care, to investigate whether the diphtheria, tetanus, and pertussis (DTaP) vaccination has an effect on specific immunoglobulin E (IgE) levels to milk, egg, or peanut. Infants will be assigned to one of two groups depending on the infant's sensitization to milk, egg, and peanut.

Official Title
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Impact of Vaccination on Th2 Immunity in Infancy

Conditions
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Food Hypersensitivity

Intervention / Treatment
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* Procedure: Skin prick allergen test
* Procedure: Blood draw


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Written informed consent from parent/guardian General good health without other known need for blood draws that would conflict with the study volume requirements Aged 5 months - 7 months, any race/ethnicity, any gender Subjects must not have yet received their third DTaP vaccination, which typically is given at 6 months of age. Subjects must have previously received two doses of the DTaP vaccination, at ages 2 months and 4 months Willingness to return for follow-up testing as defined in the protocol and consent if screening tests indicate eligibility Group 1 participants must have all of the following: A negative skin prick test to egg, milk, and peanut A negative IgE to egg, milk, and peanut Group 2 participants must have all of the following: A positive family history of allergic disease Atopic Dermatitis not requiring prescription medication A positive IgE to milk, egg, and/or peanut If Group 1 enrollment is completed first, participants must have all of the following to be enrolled in Group 2: A family history of atopy Atopic dermatitis not requiring prescription medication If Group 2 enrollment is completed first, participants must have all of the following to be enrolled in Group 1: -No personal or family history of atopic disease Exclusion Criteria: History of anemia requiring any treatment Previous allergic reaction to any food, defined as itching, rash, hives, swelling, vomiting, diarrhea, sneezing, rhinorrhea, wheezing, breathing difficulty, or passing out immediately after food ingestion. Evidence of non-IgE-mediated reaction to milk or soy (i.e. milk/soy protein intolerance) or evidence of food protein induced enterocolitis syndrome (FPIES) Severe atopic dermatitis (liberally defined as requiring prescription medication) Unable to obtain serum sample for determination of egg, milk and peanut IgE levels Use of short-acting anti-histamines (diphenhydramine, etc.) more than one time within 3 days of skin testing or on the day of skin testing Any history of intravenous or oral steroid medication Known underlying immune defect/deficiency or bleeding disorder

Ages Eligible for Study
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Minimum Age: 5 Months
Maximum Age: 7 Months

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Positive blood test to milk, egg, and/or peanut<br>Family history to atopy | Procedure: Skin prick allergen test<br>* To test for hypersensitivity to milk, egg, or peanut<br>Procedure: Blood draw<br> <br> * Other names: venipuncture;|
| Negative blood test to allergy<br>A negative skin prick test to egg, milk, and peanut and a negative Immunoglobulin E (IgE) to egg, milk, and peanut. | Procedure: Skin prick allergen test<br>* To test for hypersensitivity to milk, egg, or peanut<br>Procedure: Blood draw<br> <br> * Other names: venipuncture;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Allergen-specific IgE | Magnitude of increase of allergen-specific IgE. For each child, the maximum allergen-specific IgE change to milk, egg, or peanut will be considered as the primary endpoint. | baseline and day 28 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Milk Allergy, Egg Allergy, Peanut Allergy, Infant Vaccination