Asunto(s)
Anticuerpos Antibacterianos/inmunología , Proteínas de la Membrana Bacteriana Externa/administración & dosificación , Vacunas Bacterianas/administración & dosificación , Haemophilus influenzae/inmunología , Neisseria meningitidis/inmunología , Pentosafosfatos/administración & dosificación , Polisacáridos Bacterianos/administración & dosificación , Proteínas de la Membrana Bacteriana Externa/inmunología , Vacunas Bacterianas/inmunología , Humanos , Esquemas de Inmunización , Lactante , Pentosafosfatos/inmunología , Polisacáridos Bacterianos/inmunologíaRESUMEN
We studied an immunogen consisting of oligosaccharides derived from Haemophilus influenzae type b capsular polysaccharide (PRP) coupled to CRM197, a nontoxic relative of diphtheria toxin. Subcutaneous injections were given to eight subjects at ages 2, 4, and 6 months, simultaneously with conventional diphtheria-tetanus-pertussis (DTP) vaccine. After the first immunization, total serum anti-PRP antibodies declined in all subjects, but increased in most after the second immunization and after the third in seven of seven subjects analyzed. In these seven infants, the geometric mean level at age 9 months (0.73 micrograms/ml) exceeded by at least 40 times the means of historical control groups given DTP only or DTP plus (uncoupled) PRP vaccine. An isotype-specific assay showed that IgM antibodies increased after the first immunization with the coupled vaccine in all eight infants. Against the background of declining maternal IgG antibody, elevations in IgG antibody were detected after the second or third immunization in six of the eight. These six at age 9 to 11 months were immunized with (uncoupled) PRP vaccine, and a "boost" in anti-PRP antibody, including an IgG component, was found.
Asunto(s)
Vacunas Bacterianas/administración & dosificación , Haemophilus influenzae/inmunología , Pentosafosfatos/administración & dosificación , Polisacáridos Bacterianos/administración & dosificación , Vacunación/métodos , Anticuerpos Antibacterianos/biosíntesis , Proteínas Bacterianas/inmunología , Vacunas Bacterianas/efectos adversos , Infecciones por Haemophilus/prevención & control , Humanos , Inmunoglobulina A/análisis , Inmunoglobulina G/análisis , Inmunoglobulina M/análisis , Lactante , Pentosafosfatos/inmunología , Polisacáridos Bacterianos/inmunología , Factores de TiempoRESUMEN
Sixty 9- to 15-month-old infants were randomly assigned to receive two doses, 1 month apart, of a Haemophilus influenzae type b capsular polysaccharide-diphtheria toxoid conjugate vaccine (PRP-D) or PRP vaccine, each containing 20 micrograms PRP. There were no significant local or systemic reactions. After one dose of PRP-D, 93% of the subjects attained levels of greater than or equal to 0.15 microgram/ml and 59% achieved greater than or equal to 1 microgram/ml antibody protein. These percentages rose to 100% and 86%, respectively, after the second dose, at which time the geometric mean titer of anti-PRP antibody was 4.8 micrograms/ml. IgG anti-PRP levels were 4.3 times higher than IgM. The proportion of IgG to IgM antibody induced by PRP-D increased with age. After two doses, 33% of the PRP recipients responded with a level of greater than or equal to 0.15 microgram/ml and only 19% responded to a level of greater than or equal to 1.0 microgram/ml. One year later, all of the PRP-D recipients tested still had greater than or equal to 0.15 microgram/ml and more than half had greater than or equal to 1.0 microgram/ml antibody protein.