RESUMO
Haemophilus capsular polysaccharide-tetanus toxoid conjugate (PRP-T) and diphtheria-tetanus-pertussis (DTP) vaccines were administered in a single syringe (group 1) or separate syringes (group 2) to 284 infants at 2, 4, and 6 months of age. Group 1 infants had a slightly greater incidence of local reactions. Systemic reactions were similar. The geometric mean titers of polyribosylribitol phosphate (PRP) serum antibody concentrations after the third dose of PRP-T vaccine were 4.8 and 4.3 micrograms/ml for groups 1 and 2, respectively. Antibody responses to DTP antigens were also similar. The immunogenicity and safety of the PRP-T and DTP vaccines are equivalent when the vaccines are administered in separate syringes or the same syringe to infants.
Assuntos
Anticorpos Antibacterianos/sangue , Vacina contra Difteria, Tétano e Coqueluche/imunologia , Vacinas Anti-Haemophilus/imunologia , Haemophilus influenzae/imunologia , Toxoide Tetânico/imunologia , Tétano/imunologia , Difteria/imunologia , Vacina contra Difteria, Tétano e Coqueluche/administração & dosagem , Vacina contra Difteria, Tétano e Coqueluche/efeitos adversos , Quimioterapia Combinada , Vacinas Anti-Haemophilus/administração & dosagem , Vacinas Anti-Haemophilus/efeitos adversos , Humanos , Lactente , Toxoide Tetânico/administração & dosagem , Toxoide Tetânico/efeitos adversos , Vacinas Conjugadas/administração & dosagem , Vacinas Conjugadas/efeitos adversos , Vacinas Conjugadas/imunologia , Coqueluche/imunologiaRESUMO
To determine the immunogenicity of Haemophilus influenzae type b polysaccharide-tetanus protein conjugate vaccine in specific populations at risk, we administered vaccine to children with sickle cell anemia (n = 19; mean age, 18.3 months, malignancies (n = 18; mean age, 43.1 months), or a recent history of systemic H. influenzae type b infection (n = 17; mean age, 11.9 months). After one dose of polyribosylribitol phosphate-tetanus toxoid conjugate vaccine the geometric mean titers for polyribosylribitol phosphate antibody were 4.8 micrograms/ml (14/19 greater than 1 microgram/ml), 1.4 micrograms/ml (9/18 greater than 1 microgram/ml), and 5.6 micrograms/ml (15/17 greater than 1 microgram/ml) in these three groups, respectively. Children with sickle cell anemia or a recent history of systemic H. influenzae type b infection had polyribosylribitol phosphate antibody levels comparable to those of normal children of similar age after one or two doses of polyribosylribitol phosphate-tetanus toxoid conjugate vaccine. We conclude that this vaccine is immunogenic in children with underlying conditions associated with an increased risk of H. influenzae type b infection.
Assuntos
Anemia Falciforme/imunologia , Anticorpos Antibacterianos/biossíntese , Vacinas Bacterianas/imunologia , Infecções por Haemophilus/imunologia , Vacinas Anti-Haemophilus , Haemophilus influenzae/imunologia , Neoplasias/imunologia , Toxoide Tetânico/imunologia , Pré-Escolar , Humanos , Lactente , Neoplasias/tratamento farmacológico , Pentosefosfatos/imunologia , Polissacarídeos Bacterianos/imunologiaRESUMO
We immunized 24 patients (mean age 15.2 +/- 9.3 months) with polyribosylribitol phosphate-diphtheria toxoid conjugate vaccine (PRP-D) 2 months after a systemic Haemophilus influenzae type b infection. Children less than 24 months of age were immunized twice. Serum was obtained for antibody to PRP before and 1 or 2 months after immunization. Three of five children greater than 24 months of age and three of six children 18 to 24 months of age developed greater than 1 microgram/ml of antibody after immunization, and geometric mean postimmunization levels were significantly greater than preimmunization levels for both groups. However, two children who failed to respond to conventional PRP vaccine did not respond as expected to one dose of PRP-D. For children 7 to 17 months of age, the geometric mean PRP antibody levels increased as follows: preimmunization, 0.05 micrograms/ml; after the first dose, 0.28 micrograms/ml (p = 0.003); and after the second dose, 3.39 micrograms/ml (p = 0.001). Of 13 children, 10 developed antibody values greater than 1.0 micrograms/ml. PRP conjugate vaccines are immunogenic in young children who have not developed protective PRP antibody levels after a systemic H. Influenzae type b infection.