RESUMO
The safety and immunogenicity of Haemophilus influenzae type b-tetanus toxoid conjugate vaccine (Hib-TT) were evaluated in 77 healthy infants receiving injections at 3, 5, 7, and 18 months of age. No serious local or systemic reactions were noted. After the first injection the geometric mean Hib antibody level rose to 0.55 micrograms/ml, and each subsequent injection elicited a statistically significant rise in the geometric mean. The percentage of vaccinees with Hib antibody levels greater than 0.15 micrograms/ml serum was 75.5% after the first, 97.4% after the second, and 100% after the third Hib-TT injection. This percentage fell to 90.9% at 18 months of age but rose again to 100% after the fourth injection. Control infants (n = 10) injected with diphtheria-tetanus toxoid-pertussis vaccine only had nondetectable levels after the second injection. Hib-TT elicited increases of Hib antibody in all isotypes: IgG greater than IgM greater than IgA. Among IgG subclasses the highest increases were of IgG1. All vaccinated subjects had greater than 0.01 U/ml of TT antibody (estimated protective level) throughout the study. We conclude that Hib-TT, injected at 3, 5, 7, and 18 months, is safe and induces protective levels of antibodies during the age of highest incidence of meningitis caused by Hib.
Assuntos
Anticorpos Antibacterianos/sangue , Vacinas Bacterianas/administração & dosagem , Vacinas Anti-Haemophilus , Haemophilus influenzae/imunologia , Toxoide Tetânico/administração & dosagem , Infecções por Haemophilus/prevenção & controle , Humanos , Imunoglobulinas/análise , Lactente , Meningite por Haemophilus/prevenção & controle , GêmeosAssuntos
Anticorpos Antibacterianos/análise , Vacinas Bacterianas/administração & dosagem , Vacinas Anti-Haemophilus , Haemophilus influenzae/imunologia , Polissacarídeos Bacterianos/administração & dosagem , Toxoide Tetânico/administração & dosagem , Hidróxido de Alumínio , Cápsulas Bacterianas , Ensaio de Imunoadsorção Enzimática , Humanos , Imunoglobulina A/análise , Imunoglobulina G/análise , Imunoglobulina M/análise , Lactente , Polissacarídeos Bacterianos/imunologia , Fatores de TempoRESUMO
A new pertussis vaccine, composed of purified pertussis toxin inactivated by hydrogen peroxide and adsorbed onto aluminum hydroxide (NICHD-Ptxd), was injected into 60 children aged 18 to 23 months without a history of pertussis or pertussis vaccination. Two doses of toxoid, 10 and 50 micrograms, were used. Two injections, given 8 to 12 weeks apart, elicited increases in serum levels of antitoxin and IgG antibodies in 56 children who had no detectable antitoxin (less than 5 units) before vaccination. Four children with detectable antitoxin (greater than or equal to 5 units) before the first vaccination had pronounced antibody increases after the first dose. After the second dose, the geometric mean antitoxin concentration was 29 units with the 50 micrograms dosage and 10 units with the 10 micrograms dosage (p less than 0.001). Serum antibody levels elicited by two injections of 50 micrograms were similar to those in patients convalescing from pertussis. A third injection given to seven children 9 to 10 months after the second injection gave a booster response, with high levels of antitoxin (160 to 1280 units) and of IgG antibodies. With few exceptions the antibody response was restricted to the IgG class. Transient local reactions greater than or equal to 2 cm in diameter occurred in 14% of the children after the first dose and in 44% after the second and third doses. Moderate fever was recorded after 6% of all injections. There were no changes in peripheral blood leukocyte counts or fasting blood glucose levels measured before and 24 hours after the first injection. We conclude that NICHD-Ptxd is immunogenic in children. No serious adverse effects were noted.