Reimmunization of children immunized at 18 months of age with Haemophilus influenzae type b vaccine.
We studied the response to reimmunization at 36 months of age with Haemophilus influenzae type b (Hib) polyribosylribitol phosphate (PRP) capsular polysaccharide vaccine. Children enrolled in the study had previously received PRP or PRP plus diphtheria and tetanus toxoids with pertussis vaccine at 18 months of age. A control group of children, who received a first dose at 36 months of age, was also studied. Ninety-five percent of children receiving a second dose of vaccine had a postimmunization anti-capsular antibody level of greater than or equal to 1 microgram/mL. In comparison, 70% of 36-month-old children who received their first dose of PRP had a postimmunization level greater than or equal to 1 microgram/mL (P = 0.09). The geometric mean titer at 37 months of age was 8.64 micrograms/mL in children who had received two doses of PRP vaccine, compared with 2.19 micrograms/mL in the group who received only one dose of PRP at 36 months of age (P = 0.04). We conclude that infants immunized at 17 to 19 months of age with PRP had an excellent immunologic response to reimmunization at 36 months of age.
Glode
M P
MP
C. Henry Kempe Center for Investigative Research, Denver, Colorado.
Joffe
L S
LS
Brogden
R
R
Kuo
J
J
D000367:Age Factors; D000907:Antibodies, Bacterial / Q000032:analysis; D016667:Bacterial Capsules; D001428:Bacterial Vaccines / Q000008:administration & dosage* / Q000276:immunology; D002675:Child, Preschool; D004168:Diphtheria Toxoid / Q000008:administration & dosage; D015721:Diphtheria-Tetanus-Pertussis Vaccine; D004338:Drug Combinations / Q000008:administration & dosage; D005260:Female; D018073:Haemophilus Vaccines; D006801:Humans; D007117:Immunization, Secondary; D007223:Infant; D008297:Male; D010567:Pertussis Vaccine / Q000008:administration & dosage; D011135:Polysaccharides, Bacterial / Q000008:administration & dosage* / Q000276:immunology; D013745:Tetanus Toxoid / Q000008:administration & dosage
D000907:Antibodies, Bacterial; D001428:Bacterial Vaccines; D004168:Diphtheria Toxoid; D015721:Diphtheria-Tetanus-Pertussis Vaccine; D004338:Drug Combinations; D018073:Haemophilus Vaccines; C044237:Haemophilus influenzae type b polysaccharide vaccine; D010567:Pertussis Vaccine; D011135:Polysaccharides, Bacterial; D013745:Tetanus Toxoid