Antibody response of Mexican infants to Haemophilus influenzae type b capsular polyribosylribitol phosphate. Differences between natural and vaccine induced (oligosaccharide-CRM197 conjugated vaccine) immunization.
In this study we compared natural vs. induced Haemophilus influenzae type b (Hib) anti-capsular polyribosylribitol phosphate (PRP) antibody response in a low socioeconomic population. One hundred twenty five 2-month-old children received the complete HbOC vaccine immunization scheme and a booster dose at 15 months of age. One hundred twenty five non-immunized children served as the control group. Serum Hib anti-PRP antibody titers were determined by ELISA in all children. We found at the end of the primary immunization scheme an antibody concentration of 27.28 micrograms/ml in the immunized group vs. 7.48 micrograms/ml in the control group. The antibody response was mainly of the IgG1 class in both groups. After the booster dose the antibody concentration was 30.14 g/ml in the vaccinated group vs. 6.06 micrograms/ml in the control group (p < 0.01). Ninety nine percent of immunized and non-immunized infants had titers greater than 1 microgram/ml. These results confirm that immunization with the HbOC vaccine induces an important increase in anti-PRP specific antibody titer, but they also demonstrate that natural exposure induces responses higher than those referred as protective (1 microgram/ml).
Massó
F
F
Departamento de Biología Celular, Instituto Nacional de Cardiología Ignacio Chávez, México, D.F.
Paéz
A
A
Arista
A
A
Salmón
L
L
Montaño
L
L
D000914:Antibodies, Viral / Q000097:blood*; D016667:Bacterial Capsules; D002675:Child, Preschool; D002986:Clinical Trials as Topic; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D004890:Erythema; D005260:Female; D005334:Fever; D006192:Haemophilus Infections / Q000517:prevention & control*; D018073:Haemophilus Vaccines / Q000276:immunology* / Q000627:therapeutic use; D006193:Haemophilus influenzae / Q000276:immunology*; D006801:Humans; D007132:Immunoglobulin Isotypes / Q000097:blood; D008297:Male; D008800:Mexico; D011135:Polysaccharides, Bacterial / Q000276:immunology* / Q000627:therapeutic use; D011795:Surveys and Questionnaires; D018074:Vaccines, Conjugate / Q000008:administration & dosage / Q000276:immunology* / Q000627:therapeutic use
D000914:Antibodies, Viral; D018073:Haemophilus Vaccines; C044237:Haemophilus influenzae type b polysaccharide vaccine; D007132:Immunoglobulin Isotypes; D011135:Polysaccharides, Bacterial; D018074:Vaccines, Conjugate