Safety and immunologic response to Haemophilus influenzae type b oligosaccharide-CRM197 conjugate vaccine in 1- to 6-month-old infants.
A Haemophilus influenzae type b oligosaccharide-CRM197 conjugate (HbOC) vaccine was evaluated for safety and immunogenicity in 432 infants 1 to 6 months of age. In a multicenter study involving 10 sites in six states, infants were vaccinated with three 10-micrograms doses of HbOC at 2-month intervals. Side effects associated with vaccination were mild, transient, and occurred in fewer than 2% of the subjects. More than 90% of infants of all ages responded after two doses, and more than 98% had anti-H influenzae type b capsular polysaccharide (HbPs) antibody levels greater than or equal to 1 microgram/mL after three doses. One month after the third vaccination, the geometric mean anti-HbPs antibody levels were 16.84, 26.23, and 29.11 in infants initially vaccinated at 1 to 2, 3 to 4, and 5 to 6 months of age, respectively. A long-term antibody response was observed; more than 80% of these infants had anti-HbPs levels greater than or equal to 1 microgram/mL at 2 years of age. The HbOC generated an immune response characteristic of a protein antigen; IgG anti-HbPs antibodies of IgG1 subclass predominated and the response could be boosted. The immune sera killed H influenzae type b when evaluated in an in vitro bactericidal assay. The data indicate that HbOC safely primed and boosted the immune system of young infants, providing long-lasting protective levels of anti-HbPs antibodies.
Madore
D V
DV
Praxis Biologics, Inc, Rochester, New York 14623.
Johnson
C L
CL
Phipps
D C
DC
Popejoy
L A
LA
Eby
R
R
Smith
D H
DH
D000917:Antibody Formation; D001426:Bacterial Proteins / Q000009:adverse effects / Q000276:immunology*; D001428:Bacterial Vaccines / Q000009:adverse effects / Q000276:immunology*; D004168:Diphtheria Toxoid / Q000009:adverse effects / Q000276:immunology*; D018073:Haemophilus Vaccines; D006193:Haemophilus influenzae / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D007223:Infant; D013997:Time Factors
D001426:Bacterial Proteins; D001428:Bacterial Vaccines; D004168:Diphtheria Toxoid; D018073:Haemophilus Vaccines; C052180:Haemophilus influenzae type b-polysaccharide vaccine-diphtheria toxoid conjugate; D007074:Immunoglobulin G; C061963:HibTITER protein, Haemophilus influenzae