Bacille Calmette-Guérin (BCG) Vaccine and Atopy

The Effect of Giving BCG Vaccine at Birth to Low Birth-weight Infants on Development of Allergy and Asthma in Childhood - Follow up of a Randomised Trial in Guinea-Bissau

The prevalence of asthma and allergic diseases is increasing worldwide. Infections and vaccinations in childhood may have an impact on the subsequent development of asthma and allergy. In Guinea-Bissau, the investigators previously found that Bacille Calmette-Guérin (BCG) vaccine was associated with reduction in atopy. Since then the investigators have conducted a randomised trial of BCG vaccine given at birth to low birth-weight infants. The present study aims to follow up children enrolled in the BCG randomised trial to assess for asthma and allergy later in childhood. Based on previous observations, the investigators expect children allocated to receive BCG at birth will have a reduction in allergy profile when compared to children who did not receive BCG at birth.

Study Overview

• Status: Completed
• Conditions: Food Hypersensitivity; Asthma; Eczema

Detailed Description

Background: Prevalence of asthma and allergy is increasing worldwide, and the cause is unclear. Previous work by the Bandim Health Project and others has identified that infections and routine childhood vaccinations have an impact on the development of atopic sensitisation and allergic symptoms later in life. A number of these studies have found association between BCG vaccination and reduction in atopy and allergy. Only one randomised trial has been conducted of BCG vaccine to protect against allergy with inconclusive results. The present project provides the opportunity to follow-up children born low birth-weight who were randomised to receive BCG vaccine at birth or to receive BCG later in infancy as part of regular care.

Hypothesis:

• Children given BCG vaccine at birth will have reduced prevalence of positive skin-prick test and allergic symptoms when compared with children who did not receive BCG at birth
• Early BCG vaccination will be associated with reduced prevalence of positive skin prick test and allergic symptoms
• Early DTP vaccination will be associated with increased prevalence of positive skin-prick tests and allergic symptoms

Objectives:

• to examine the effects of environmental factors, including BCG, DTP and measles vaccines, on atopy (determined by skin-prick tests) and symptoms of asthma, eczema and food allergy
• to examine the sex-differential effects of vaccination on atopy and allergic symptoms
• to determine the association between faecal microbial diversity, atopy and food allergy

Methods: children previously enrolled in NCT00146302 will followed up at home (currently aged 3-9 years) and tested for atopic sensitisation with skin-prick tests and presence of allergic symptoms determined by questionnaire.

Sample size: 812 children from the Bandim Health Project study area were enrolled in the randomised trial. The investigators anticipate to be able to follow up approximately 487 of these children, which will have the power to detect a 30% difference in atopic sensitisation between groups.

• Study Type: Observational
• Enrollment (Anticipated): 487

Contacts and Locations

Study Locations

• Guinea-Bissau
  • Bandim, Guinea-Bissau
    • Bandim Health Project

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 3 years to 9 years (Child)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Probability Sample

Study Population

Children previously enrolled in NCT00146302 living within Bandim Health Project study area, Bissau

Description

Inclusion Criteria:

• Previous enrolment in NCT00146302
• Living within Bandim Health Project study area

Exclusion Criteria:

• Children with known history of anaphylaxis
• Children with skin infections or severe skin conditions for who SPT could not be reliably performed
• Children currently taking anti-histamine medication

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Retrospective

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort
Low birth-weight cohort; Children previously enrolled in randomised trial NCT00146302 who are currently living within the Bandim Health Project study area

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Skin prick test	Skin prick tests to common aero and food allergen	Single observation at time of consent - DAY 1

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Symptoms of asthma	Symptoms of asthma using questions modified from ISAAC	Single observation at time of consent - DAY 1
Symptoms of eczema	Eczema symptoms using questions modified from ISAAC	Single observation at time of consent - DAY 1
Symptoms of food allergy	Symptoms of food allergy using questions modified from the Health Nuts study	Single observation at time of consent - DAY 1

Collaborators and Investigators

• Sponsor: Bandim Health Project
• Collaborators: Murdoch Childrens Research Institute
• Investigators: Principal Investigator: Peter Aaby, DMSc, Bandim Health Project

Publications and helpful links

General Publications

• Kiraly N, Benn CS, Biering-Sorensen S, Rodrigues A, Jensen KJ, Ravn H, Allen KJ, Aaby P. Vitamin A supplementation and BCG vaccination at birth may affect atopy in childhood: long-term follow-up of a randomized controlled trial. Allergy. 2013 Sep;68(9):1168-76. doi: 10.1111/all.12216. Epub 2013 Aug 31.

Helpful Links

• Related Info

Study record dates

Study Major Dates

• Study Start: October 1, 2011
• Primary Completion (Actual): December 1, 2011
• Study Completion (Actual): December 1, 2011

Study Registration Dates

• First Submitted: August 12, 2011
• First Submitted That Met QC Criteria: August 19, 2011
• First Posted (Estimate): August 22, 2011

Study Record Updates

• Last Update Posted (Estimate): December 29, 2011
• Last Update Submitted That Met QC Criteria: December 27, 2011
• Last Verified: December 1, 2011

More Information

Terms related to this study

• Keywords: Allergy; Vaccination; Guinea-Bissau; Atopy; Bacille Calmette-Guérin; DTP
• Additional Relevant MeSH Terms: Respiratory Tract Diseases; Immune System Diseases; Lung Diseases; Hypersensitivity, Immediate; Bronchial Diseases; Lung Diseases, Obstructive; Respiratory Hypersensitivity; Hypersensitivity; Asthma; Food Hypersensitivity
• Other Study ID Numbers: 2011-BHP-LBW-BCG-atopy