摘要:

Background.Haemophilus influenzaetype b (Hib) conjugate vaccines have successfully reduced the burden of invasive Hib disease in developed countries; however, their effectiveness in countries with a high incidence of pediatric HIV-1 is unknown.Methods.The effectiveness of Hib conjugate vaccine was prospectively evaluated in South African children. The burden of invasive Hib disease in children <1 year old was compared in 2 cohorts. The first cohort included 22 000 African children born in 1997 [969 (4.45%) of whom were estimated to be HIV-1-infected] who were not vaccinated with Hib conjugate vaccine. This group was compared with 19 267 children [1162 (6.03%) of whom were estimated to be HIV-1-infected] vaccinated at 6, 10 and 14 weeks of age with an Hib conjugate vaccine [TETRAMUNE (polyribosylribitol phosphate-CRM197-diphtheria-tetanus toxoids-whole cell pertussis)] between March, 1998, and June, 1999.Results.The estimated burden of invasive Hib disease in nonimmunized HIV-1-infected children <1 year of age was 5.9-fold [95% confidence interval (95% CI), 2.7 to 12.6] higher than in HIV-1-uninfected children. The overall estimated effectiveness of Hib conjugate vaccine in fully vaccinated children <1 year of age was 83.2% (95% CI 60.3 to 92.9). Vaccine effectiveness was significantly reduced in HIV-1- infected [43.9% (95% CI −76.1 to 82.1)] compared with uninfected children [96.5% (95% CI 74.4 to 99.5);P< 10−5]. Among three of the fully vaccinated HIV-1-infected children who developed invasive Hib disease, the anti-Hib polyribosylribitol phosphate serum antibody concentrations were 0.23, 0.25 and 0.68 &mgr;g/ml.Conclusion.Although the Hib conjugate vaccine was less effective among HIV-1-infected than among uninfected children, it was 83% effective in preventing overall invasive Hib disease and therefore should be considered for inclusion in the routine vaccination schedule by other African countries.

ISSN:0891-3668    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Background.We conducted the first trial to assess the safety and immunogenicity of an oral, killed enterotoxigenicEscherichia coliplus cholera toxin B-subunit vaccine in children <2 years old.Methods.Three doses of vaccine or killedE. coliK-12 control were given at 2-week intervals to 64 Egyptian infants, 6 to 18 months old, in a randomized, double blind manner. Adverse events were monitored for 3 days after each dose. Blood was collected before immunization and 7 to 10 days after each dose to assess vaccine-specific serologic responses.Results.There was no statistically significant intergroup difference in the percentage of subjects reporting the primary safety endpoint (diarrhea or vomiting) after the first (31%, vaccine; 30%, control) or third (14%, vaccine; 18%, control) dose, whereas there was a trend toward greater reporting in the vaccine group after Dose 2 (36%, vaccine; 18%, control;P= 0.052). The percentage of children showing IgA seroconversion after any dose was higher in the vaccine than the control group for recombinant cholera toxin B-subunit (97%vs.46%), colonization factor antigen I (61%vs.18%) and coli surface antigen 4 (39%vs.4%) (P< 0.001 for each comparison). IgG seroconversion rates in the vaccine and control groups were 97 and 21% to recombinant cholera toxin B-subunit (P< 0.001), 64 and 29% for colonization factor antigen I (P< 0.01), 53 and 21% for coli surface antigen 2 (P< 0.05) and 58 and 4% for coli surface antigen 4 (P< 0.001), respectively. The third vaccine dose was followed by augmented IgG antitoxin titers.Conclusion.The oral enterotoxigenicE. colivaccine was safe and immunogenic in this setting in Egyptian infants.

ISSN:0891-3668    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Objectives.To study the correlation between serum concentrations of adrenocorticotrophic hormone (ACTH) and cortisol in relation to severity of disease in children with meningococcal sepsis.Methods.Subjects were children with meningococcal sepsis, admitted to the pediatric intensive care unit. Clinical data, laboratory values and blood samples were selected. Arterial cortisol, ACTH, interleukin 6 and tumor necrosis factor alpha concentrations were measured on admission and studied for their relation to severity of disease (sepsis, septic shock/survivors, septic shock/nonsurvivors).Results.Seventy-two patients fulfilled the criteria for meningococcal sepsis. Sixty-two of these children with positive blood cultures ofNeisseria meningitidis,who were not treated with corticosteroids before admission, were included. Fifty of the 62 patients had septic shock. Twelve of those children (24%) died. The median age of the subjects was 2.6 years (range, 0.3 to 16.1 years). Cortisol values were significantly lower in nonsurvivors (median, 654 nmol/l) than in survivors (median, 2184 nmol/l) (P< 0.01). ACTH values were significantly higher in children who died (median, 1271 ng/l) than in survivors (85 ng/l) (P< 0.01). The median cortisol:ACTH ratio decreased significantly depending on the disease severity categories.Conclusions.Low serum cortisol concentrations in combination with high ACTH concentrations are associated with poor outcome in children with severe meningococcal disease.

ISSN:0891-3668    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Background.We used the large clinical database that supported the development of Oka/Merck varicella vaccine to study the relationship between the primary varicella antibody response, as determined by gpELISA, an enzyme-linked immunosorbent assay that detects antibodies to varicella-zoster virus (VZV) glycoprotein, and the subsequent risk of postvaccination breakthrough varicella.Methods.We vaccinated 1164 healthy children with a single dose of varicella vaccine containing 2900 to 9000 plaque-forming units/dose. The primary immune response to vaccination was determined by gpELISA 6 weeks after vaccination. Subjects were followed annually for 7 years to ascertain cases of breakthrough varicella.Results.The estimated vaccine efficacy among children with a 6-week postvaccination antibody titer of ≥5 gpELISA units was 95.5% (95% confidence interval, 94.2%, 96.8%) compared with 83.5% (95% confidence interval, 76.9%, 89.5%) for subjects with a titer of <5 gpELISA units. Children with a 6-week postvaccination antibody titer of <5 gpELISA units were 3.5 times more likely than those with a titer of ≥5 gpELISA units to develop breakthrough varicella.Conclusions.We identified a 6-week postvaccination antibody titer of ≥5 gpELISA units as an approximate correlate of protection. In addition we established an accelerated failure time model based on log normal hazard that predicted varicella breakthrough rates based on the distribution of 6-week postvaccination varicella antibody titers.

ISSN:0891-3668    

出版商:OVID    

年代:2002

数据来源: OVID

ISSN:0891-3668    

出版商:OVID    

年代:2002

数据来源: OVID

ISSN:0891-3668    

出版商:OVID    

年代:2002

数据来源: OVID

ISSN:0891-3668    

出版商:OVID    

年代:2002

数据来源: OVID

ISSN:0891-3668    

出版商:OVID    

年代:2002

数据来源: OVID

ISSN:0891-3668    

出版商:OVID    

年代:2002

数据来源: OVID

ISSN:0891-3668    

出版商:OVID    

年代:2002

数据来源: OVID