All issues > Volume 38(9); 1995

Original Article

J Korean Pediatr Soc. 1995;38(9):1201-1209. Published online September 15, 1995.

Natural Anti-PRP Antibody Levels to Haemophilus Influenzae Type b(Hib) and Changes of Antibody Levels after Three Doses of Vacination

Eun Sun ES Yoo¹, Eun Ae EA Park¹, Gyoung Hee GH Kim¹

¹Department of Pediatrics, Ewha Womans University College of Medicine, Seoul, Korea

Abstract

Purpose
: The Haemophilus influenzae type b(Hib) was the most common cause of meningitis and invasive bacterial disease mainly in children 2 months to 5 years old in the United States. The conjugated Hib vaccines have recently been licensed by the US Food and Drug Administration for routine use in infants beginning at 2 months of age, and the Infectious Disease Committee of the American Academy of Pediatrics have of pediatric pathogen is lower compared with those of western countries. The purpose of this study is to determine the natural immunity to Haemophilus influenzae type b(Hib) in children and the efficacy of the PRP-T(Pasteur-Marieux Serum and Vaccine) conjugate Haemophilus influenzae type b vaccine.
Methods
: We measured the serum antibody levels to capsular polysaccharide(PRP) of Haemophilus influenzae type b in 155 unvaccinated healthy children(control group), age ranged from 1 to 96 months. We also measured same antibody in the sera of 156 infants who received PRP-T was given as three doses at 2, 4 and 6 months of age. The titration of antibody to capsular polysaccharide(PRP) was performed by enzymelinked immunosorbent assay.
Results
: The results were as follows. 1) The geometric mean titers of anti-PRP antibody below the protective level in 3-11 month age group and increased progressively in 12-96 month age group. So, linear correlation between anti-PRP antibody and age was significant (r=0.31, p<0.05). 2) Thirty four percent of the total subjects in 0-2 month age group had an antibody level considered to be protective(015g/ml). Seropositive rate was 8.3% in 5-6 month age group, and increased progressively to 88.9% in 73-84 month age group. 3) Anti-PRP antibody is significantly higher in vaccination group compared with control group (p<0.05). 4) Anti-PRP antibody and number of subjects showing antibody levels of 1.0g/ml)
Conclusion
: Although linear correlation between anti-PRP antibody and age was present, the geometric mean titers of anti-PRP antibody were below the protective level in the 3-11 month age group. So, active immunization to H. influenzae type b can be recommanded at 2 months after birth. And protective antibody level can be obtained after 2 to 3 times of PRP-T vaccine. However, further epider

Keywords :Haemophilus influenzae type b, Natural antibody, Efficacy of PRP-T vaccine