ABSTRACT
There are limited data concerning safety and immunogenicity of Haemophilus influenzae type b polysaccharide vaccine in children with sickle cell disease. Ninety-eight patients with sickle cell disease (65 with SS phenotype, 23 with SC phenotype, and 10 with S beta-thalassemia) 1.5 to 20 years of age were given 25 micrograms of vaccine subcutaneously. The vaccine was well tolerated; mild side effects were observed in 6 of 98 (6.1%) children. In addition, one patient with a recent vasoocclusive crisis was hospitalized because of fever and vasoocclusive crisis 8 hours after vaccination. Prevaccination anticapsular antibody concentrations (by radioimmunoassay) were less than 0.15 microgram/mL in 7 of 11 children 18 to 24 months of age (geometric mean 0.17 microgram/mL), in 10 of 25 children 2 to 5 years of age (geometric mean 0.36 microgram/mL), and in 3 of 50 patients 6 to 20 years of age (geometric mean 1.03 microgram/mL). Inadequate response (1- to 2-month postvaccination antibody level less than 1 microgram/mL) was found in 3 of 5 children 18 to 24 months of age (geometric mean 1.74 microgram/mL), in 8 of 21 children 2 to 5 years of age (geometric mean 2.20 micrograms/mL), and in 2 of 49 patients 6 to 20 years of age (geometric mean 18.03 micrograms/mL). Six months after vaccination, greater than 1 microgram/mL of antibody was present in the 2 children 6 to 20 years of age with inadequate response but not in the 7 children 2 to 5 years of age with inadequate response.(ABSTRACT TRUNCATED AT 250 WORDS)
Subject(s)
Anemia, Sickle Cell , Bacterial Vaccines , Haemophilus Infections/prevention & control , Haemophilus influenzae/immunology , Vaccination , Adolescent , Adult , Anemia, Sickle Cell/immunology , Antibodies, Bacterial/analysis , Bacterial Vaccines/administration & dosage , Bacterial Vaccines/classification , Child , Child, Preschool , Female , Humans , Infant , Male , Polysaccharides, Bacterial , Time FactorsABSTRACT
OBJECTIVE: To determine the safety and immunogenicity of Haemophilus influenzae type b conjugate vaccine in children with sickle cell disease. RESEARCH DESIGN: Prospective, nonrandomized, nonblinded study. SETTING: Hospital-based, comprehensive sickle cell center. PATIENTS: Children with sickle cell disease aged 18 months to 18 years who were previously unvaccinated or had an inadequate or waning response to H influenzae type b polysaccharide vaccine. SELECTION PROCEDURES: Consecutive eligible patients. INTERVENTIONS: Vaccination and observation for adverse effects. Blood samples were taken before and 1 to 2 and 6 months after vaccination to measure anticapsular antibody levels. MEASUREMENTS AND RESULTS: Vaccination was well tolerated. One hundred percent and 96% of the 31 immunized children had postvaccination anticapsular antibody concentrations of greater than 0.15 and 1.0 mg/L, respectively. Six months after vaccination, 100% and 89% of children had these antibody concentrations. CONCLUSIONS: H influenzae type b conjugate vaccines are safe and highly immunogenic in children with sickle cell disease. It is likely that these vaccines will be protective against invasive H influenzae type b disease.