Related Experiment Videos
Response to Haemophilus influenzae type B conjugate vaccine in children undergoing splenectomy
D M Ambrosino1, M Y Lee, D Chen
1Laboratory of Infectious Diseases, Dana-Farber Cancer Institute, Boston, MA 02115.
Insights
Children without spleens face higher infection risks. A study showed Haemophilus influenzae type b (HIB) conjugate vaccine provides a superior immune response in children undergoing splenectomy compared to the polysaccharide HIB vaccine.
Area of Science:
- Pediatric Infectious Diseases
- Immunology
- Vaccinology
Background:
- Asplenic children are highly susceptible to encapsulated bacterial infections, including Haemophilus influenzae type b (HIB).
- Vaccination with polysaccharide vaccines is recommended for asplenic children, but newer conjugate vaccines offer improved immunogenicity.
- The HIB polysaccharide-conjugate vaccine, linked to diphtheria toxoid, was introduced in 1987.
Purpose of the Study:
- To evaluate the immune response in children undergoing splenectomy after immunization with the HIB polysaccharide-conjugate vaccine.
- To compare the immunogenicity of the HIB-conjugate vaccine with the pure polysaccharide HIB vaccine in pediatric populations.
Main Methods:
- Thirteen children (aged 3-19) scheduled for splenectomy received the HIB-conjugate vaccine before surgery; serum was collected post-splenectomy.
- Fifteen healthy control children (aged 2-14) received the pure polysaccharide HIB vaccine.
- Geometric mean IgG anti-HIB antibody concentrations were measured and compared between the two groups.
Main Results:
- Children undergoing splenectomy who received the HIB-conjugate vaccine demonstrated a significantly higher geometric mean IgG anti-HIB antibody concentration (48,106 ng/mL) compared to controls (10,786 ng/mL) (P = .01).
- All immunized children achieved antibody levels (≥1,000 ng/mL) considered protective against HIB infection.
Conclusions:
- The HIB polysaccharide-conjugate vaccine elicits a robust immune response in children undergoing splenectomy.
- Immunization with the HIB-conjugate vaccine is recommended for children undergoing splenectomy due to its superior immunogenicity.
Abstract:
Asplenic children are at increased risk for serious infection with polysaccharide encapsulated bacteria including Haemophilus influenzae type b (HIB), Streptococcus pneumoniae, and Neisseria meningitidis. Immunization with polysaccharide vaccines is recommended for children undergoing splenectomy. In 1987 a new more immunogenic HIB vaccine was licensed in the US to replace the pure HIB polysaccharide vaccine that was licensed in 1985. This polysaccharide-conjugate vaccine consists of the HIB polysaccharide linked to a protein carrier, diphtheria toxoid. Therefore, we evaluated the immune response of children undergoing splenectomy to HIB-conjugate vaccine. Thirteen children (7 with Hodgkin's disease, 4 with idiopathic thrombocytopenia, 2 with hereditary spherocytosis) aged 3 to 19 years were immunized with HIB-conjugate vaccine prior to splenectomy and serum was obtained following splenectomy. In addition, 15 healthy control children aged 2 to 14 years were immunized with the pure polysaccharide HIB vaccine for comparison. The patients undergoing splenectomy who received the HIB-conjugate vaccine had a geometric mean IgG anti-HIB antibody concentration of 48,106 ng/mL versus 10,786 ng/mL for the control patients who received the pure polysaccharide vaccine (P = .01). The presumed protective level of antibody is 1,000 ng/mL and all children were well above this concentration. Therefore, we propose that children undergoing splenectomy be immunized with an HIB-conjugate vaccine.