Evaluation of humoral response to heptavalent pneumococcal conjugate vaccine in HIV-infected children.
OBJECTIVE
Invasive pneumococcal disease is a major cause of death in HIV-infected children. The objective of the study was to assess the quantitative antibody response to the seven pneumococcal serotypes of heptavalent pneumococcal conjugate vaccine in a group of HIV-infected children.


METHODS
Study comprising 40 HIV-infected children aged between 2 and 9 years followed up in a specialized outpatient clinic in São Paulo, Brazil, between 2002 and 2003. Enzyme immunoassay (ELISA) was used to measure IgG antibody titers against pneumococcus capsule. Antibodies were measured immediately before and 1 month after the second dose of the vaccine. Two response criteria were used: IgG titers >or=1.3 microg/mL in the post-immunization serology and an increase of at least 4or=-fold in post- compared to pre-immunization serology.


RESULTS
For the first criterion (>or=1.3 microg/mL), 26 (65%) children had serological response to the vaccine, 12 (30%) showed post-immunization IgG titers of at least 1.3 microg/mL for all seven serotypes studied. For the second criterion studied (>or=4-fold increase in post- compared to pre-immunization titers for four serotypes or more), serological response was seen in 15 (37.5%) children.


CONCLUSIONS
Overall response to the heptavalent pneumococcal conjugate vaccine was adequate, showing a statistically significant increase in the post-immunization geometric mean titers for the seven serotypes studied.
Costa
Isabel de Camargo
Ide C
Instituto da Criança do Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brasil.
Guilardi
Fabiana
F
Kmiliauskis
Mariana Acenjo
MA
Arslanian
Christina
C
Baldacci
Evandro Roberto
ER
D017088:AIDS-Related Opportunistic Infections / Q000276:immunology / Q000517:prevention & control*; D000907:Antibodies, Bacterial / Q000096:biosynthesis / Q000097:blood; D002648:Child; D002675:Child, Preschool; D004797:Enzyme-Linked Immunosorbent Assay; D015658:HIV Infections / Q000276:immunology*; D006801:Humans; D016867:Immunocompromised Host; D007074:Immunoglobulin G / Q000097:blood*; D011008:Pneumococcal Infections / Q000276:immunology / Q000517:prevention & control*; D022242:Pneumococcal Vaccines / Q000008:administration & dosage / Q000276:immunology*; D011135:Polysaccharides, Bacterial / Q000276:immunology; D012703:Serotyping; D013296:Streptococcus pneumoniae / Q000276:immunology*; D018074:Vaccines, Conjugate / Q000008:administration & dosage / Q000276:immunology
C414006:23-valent pneumococcal capsular polysaccharide vaccine; D000907:Antibodies, Bacterial; D007074:Immunoglobulin G; D022242:Pneumococcal Vaccines; D011135:Polysaccharides, Bacterial; D018074:Vaccines, Conjugate