Investigating Healthy Egyptian Infants for BCG vaccine Induced Immunoprotection against TB

Abstract

In Egypt, TB still must be addressed and handled as a health problem affecting large sectors in the society, especially the poor and the vulnerable. Despite controversies BCG vaccination has stood the test of time. World Health Organization continues to recommend its use in infant immunization programme in countries with heavy endemicity and where threatening HIV epidemic is an emerging problem with more than 85% efficacy against hematogenous spread of the disease and ≥50% efficacy even against pulmonary tuberculosis (Parthasarathy, 2003) This study is designed to investigate the rate of immune-protection against TB conferred by the currently used BCG vaccine in a group of healthy Egyptian infants. The study was designed as a cross sectional study which was carried out at the outpatient clinic of Children’s hospital, Faculty of Medicine, Ain Shams University. The study included 30 healthy infants 14-24 months old after exclusion of clinical criteria suggestive of immunodeficiency. They were 20 males and 10 females. They were all BCG vaccinated according to the Extended Program of Immunization (EPI) applied in Egypt. The enrolled infants were clinically evaluated and subjected to laboratory investigations including, complete blood count with manual white blood cell differential count, in-vivo T cell function test (Candida and tuberculin intradermal skin tests) and in-vitro assessment of T cell function by measurement of IFN-γ in the supernatant of cultured mononuclear cells before and after PPD and PHA stimulation.