Immunogenicity of neonatal BCG vaccination in children entering primary school.
This study has been designed to evaluate the immunogenicity of neonatal BCG-vaccination in children at the age of 7 to 8 years, by skin test using Purified Protein Derivative (PPD), as BCG vaccination at birth is a part of routine program of immunization in our country, Iran; we decided to study its efficacy and also tried to determine if there is any correlation between PPD-test results and BCG scar size. This is a comparative study on 150 children (94 males and 56 females) at the age of 7 to 8 years, who possess neonatal-BCG scar. They were chosen from several primary schools in Tabriz-Iran, by simple random sampling and tested with 0.1 mL of 5-unit-PPD solution (a product of Iran Institute of Razi); then observations recorded. The average diameter of BCG scars were 7.03 mm in girls, 5.45 mm in boys and 6.05 for all. The diameter of induration area resulted from PPD-test after 72 h was less than 5 mm in 95.33% and 5-9 mm in 4.66% of studied children; there was no case with induration area of 10 mm or more at all. Every child who developed an induration area of 5 mm or more by PPD test, had a BCG scar with the diameter of 5 mm or more. There was a statistically meaningful direct correlation between sizes of neonatal-BCG scar and diameter of induration area after PPD-test (r = 0.21 and p = 0.008). This study shows that reactivity to PPD test (and probably immunity against tuberculosis) decreases as age increases; therefore it seems to be necessary to repeat BCG-vaccination in children at the age of entering primary school.
Sakha
K
K
Department of Pediatrics, Tabriz University of Medical Sciences, Tabriz, Iran.
Behbahan
A G
AG
D001500:BCG Vaccine / Q000276:immunology*; D002648:Child; D002921:Cicatrix / Q000276:immunology; D005260:Female; D006801:Humans; D007115:Immunization Schedule; D007223:Infant; D008297:Male; D009163:Mycobacterium bovis / Q000276:immunology; D012574:Schools; D013997:Time Factors; D014373:Tuberculin / Q000378:metabolism; D014374:Tuberculin Test / Q000379:methods; D014376:Tuberculosis / Q000276:immunology / Q000517:prevention & control; D014611:Vaccination
D001500:BCG Vaccine; D014373:Tuberculin