987 resultados para Vaccine Effectiveness


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Background Despite the WHO recommendation that the 2010-2011 trivalent seasonal flu vaccine must contain A/California/7/2009/H1N1-like virus there is no consistent data regarding its immunogenicity and safety in a large autoimmune rheumatic disease (ARD) population. Methods 1668 ARD patients (systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), ankylosing spondylitis (AS), systemic sclerosis, psoriatic arthritis (PsA), Behcet`s disease (BD), mixed connective tissue disease, primary antiphospholipid syndrome (PAPS), dermatomyositis (DM), primary Sjogren`s syndrome, Takayasu`s arteritis, polymyositis and Granulomatosis with polyangiitis (Wegener`s) (GPA)) and 234 healthy controls were vaccinated with a non-adjuvanted influenza A/California/7/2009(H1N1) virus-like strain flu. Subjects were evaluated before vaccination and 21 days post-vaccination. The percentage of seroprotection, seroconversion and the factor increase in geometric mean titre (GMT) were calculated. Results After immunisation, seroprotection rates (68.5% vs 82.9% p < 0.0001), seroconversion rates (63.4% vs 76.9%, p < 0.001) and the factor increase in GMT (8.9 vs 13.2 p < 0.0001) were significantly lower in ARD than controls. Analysis of specific diseases revealed that seroprotection significantly reduced in SLE (p < 0.0001), RA (p < 0.0001), PsA (p=0.0006), AS (p=0.04), BD (p=0.04) and DM (p=0.04) patients than controls. The seroconversion rates in SLE (p < 0.0001), RA (p < 0.0001) and PsA (p=0.0006) patients and the increase in GMTs in SLE (p < 0.0001), RA (p < 0.0001) and PsA (p < 0.0001) patients were also reduced compared with controls. Moderate and severe side effects were not reported. Conclusions The novel recognition of a diverse vaccine immunogenicity profile in distinct ARDs supports the notion that a booster dose may be recommended for diseases with suboptimal immune responses. This large study also settles the issue of vaccine safety. (ClinicalTrials.gov #NCT01151644)

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Streptococcus pyogenes infections remain a health problem in several countries due to poststreptococcal sequelae. We developed a vaccine epitope (StreptInCor) composed of 55 amino acids residues of the C-terminal portion of the M protein that encompasses both T and B cell protective epitopes. The nuclear magnetic resonance (NMR) structure of the StreptInCor peptide showed that the structure was composed of two microdomains linked by an 18-residue alpha-helix. A chemical stability study of the StreptInCor folding/unfolding process using far-UV circular dichroism showed that the structure was chemically stable with respect to pH and the concentration of urea. The T cell epitope is located in the first microdomain and encompasses 11 out of the 18 alpha-helix residues, whereas the B cell epitope is in the second microdomain and showed no alpha-helical structure. The prediction of StreptInCor epitope binding to different HLA class II molecules was evaluated based on an analysis of the 55 residues and the theoretical possibilities for the processed peptides to fit into the P1, P4, P6, and P9 pockets in the groove of several HLA class II molecules. We observed 7 potential sites along the amino acid sequence of StreptInCor that were capable of recognizing HLA class II molecules (DRB1*, DRB3*, DRB4*, and DRB5*). StreptInCoroverlapping peptides induced cellular and humoral immune responses of individuals bearing different HLA class II molecules and could be considered as a universal vaccine epitope.

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Background. The purpose of this study was to analyze the cost-effectiveness of cisplatin-based chemoradiation compared to radiation therapy (RT) alone to treat patients with advanced head and neck cancer in Brazil. Methods. Data were collected retrospectively from the medical records of 33 patients treated with RT alone (strategy 1) and from 29 patients treated with cisplatin-based chemoradiation (strategy 2). The Brazilian National Health System (Sistema Unico de Saude [SUS]) reimbursement parameters perspective was considered, and the effectiveness was measured in years of disease-free life gained. One-way sensitivity analysis was performed to determine robustness of this study. Results. In strategy 1, there were 31% of the patients who lived without disease progression for more than 13 months after treatment, compared to 58% of patients in strategy 2. According to SUS parameters, the total cost per patient in strategy 1 was $1167.00 U.S. dollars and in strategy 2, it was $2058.00 U.S. dollars. Incremental cost-effectiveness ratio (ICER) was $3303.00 U.S. dollars per life-year gained. Conclusion. Cisplatin-based chemoradiation proved to be more cost-effective than RT alone. (C) 2010 Wiley Periodicals, Inc. Head Neck 33: 1199-1205, 2011

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Although acquisition of anti-pertussis antibodies by the newborn via placental transfer has been demonstrated, a subsequent recrudescence of pertussis infection is often observed, particularly in infants. The present study investigated the passive transfer of anti-pertussis IgG and IgA antibodies to term newborns and their ability to neutralize bacterial pathogenicity in an in vivo experimental model using mice intracerebrally challenged with viable Bordetella pertussis. Forty paired samples of maternal/umbilical cord sera and colostrum were obtained. Anti-pertussis antibodies were analysed by immunoenzymatic assay and by Immunoblotting. Antibody neutralizing ability was assessed through intracerebral B. pertussis challenges in mice. Anti-pertussis IgG titres were equivalent in both maternal and newborn sera (medians = 1:225 and 1:265), with a transfer rate of 118%. The colostrum samples had variable specific IgA titres (median = 1:74). The immunoblotting assays demonstrated identical recognition profiles of paired maternal and newborn serum pools but different bacterial recognition intensities by colostrum pools. In the animal model, significant differences were always observed when the serum and colostrum samples and pools were compared with the positive control (P < 0.05). Unlike samples with lower anti-pertussis titres, samples with high titres showed protective capacities above 50%. Pertussis-absorbed serum and colostrum pools protected 30% of mice and purified IgG antibodies protected 65%. Both pooled and single-sample protective abilities were correlated with antibody titres (P < 0.01). Our data demonstrated the effectiveness of anti-pertussis antibodies in bacterial pathogenesis neutralization, emphasizing the importance of placental transfer and breast-feeding in protecting infants against respiratory infections caused by Bordetella pertussis.

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Because of the advent of a new influenza A H1N1. strain, many countries have begun mass immunisation programmes. Awareness of the background rates of possible adverse events will be a crucial part of assessment of possible vaccine safety concerns and will help to separate legitimate safety concerns from events that are temporally associated with but not caused by vaccination. We identified background rates of selected medical events for several countries. Rates of disease events varied by age, sex, method of ascertainment, and geography. Highly visible health conditions, such as Guillain-Barre syndrome, spontaneous abortion, or even death, will occur in coincident temporal association with novel influenza vaccination. On the basis of the reviewed data, if a cohort of 10 million individuals was vaccinated in the UK, 21.5 cases of Guillain-Barre syndrome and 5.75 cases of sudden death would be expected to occur within 6 weeks of vaccination as coincident background cases. In female vaccinees in the USA, 86.3 cases of optic neuritis per 10 million population would be expected within 6 weeks of vaccination. 397 per 1 million vaccinated pregnant women would be predicted to have a spontaneous abortion within 1 day of vaccination.

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Whether gestational immunization of HIV-infected mothers with the 23-valent pneumococcal polysaccharide vaccine (PPV) confers maternal and infant early life, passive protection is not known. We evaluated safety, immunogenicity and placental transfer of antibodies in 44 HIV-infected women. Pneumococcal IgG antibodies against serotypes 1, 3, 5, 613, 9V, and 14 were measured in mothers (pre-vaccination and at delivery), and infants (at birth, 1, 2, 3, and 6 months). PPV was safe and immunogenic in mothers. Newborns received 46-72% of maternal antibody titers. Overall, infants had antibody levels lower than protective by 2 months of age. Alternative pneumococcal vaccination of HIV-infected pregnant women should be explored with the aim of prolonging passive protection in their infants. (C) 2009 Elsevier Ltd. All rights reserved.

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Pneumococcal vaccination has been recommended for immunocompromised children, including patients with chronic kidney disease. We determined pneumococcal immunoglobulin (Ig) G antibodies to serotypes 4, 6B, 9V, 14, 18C, 19F, and 23F before and after 48 pediatric patients with chronic renal failure were administered heptavalent conjugated pneumococcal vaccine. The patients were between 1 and 9 years of age and were separated into a conservative treatment group (Group 1) and a dialysis group Group 2). The antibody response to the vaccinal serotypes was evaluated by measuring antibody concentrations before the first dose and 60 days after the second one. Pre-vaccinal IgG concentrations >= 0.35 mu g/ml were detected for all serotypes in at least 50% of the patients in both groups. Patients from both groups showed a statistically indistinguishable behavior in terms of the medians of post-vaccination IgG levels. An ""adequate"" vaccine response was defined as a post-immunization level of specific pneumococcal serotype antibody >= 0.35 mu g/ml, based on the World Health Organization`s (WHO) protective antibody concentration definition for pneumococcal conjugate vaccines, or on a fourfold increase over baseline for at least five of the seven antigens of the vaccine. An ""adequate"" vaccinal response was obtained in 100% of the patients of both groups using WHO`s definition, or in 45.8% of Group 1 patients and 37.5% of Group 2 patients when the criterion was a fourfold antibody increase over baseline antibody concentrations.

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Vaccines capable of inducing mucosal immunity in early postnatal life until adulthood, protecting early sexual initiation, should be considered as strategies to vaccination against HIV. The HIV-1 GAG protein as a chimera with the lysosome-associated membrane protein (LAMP/gag), encoded by a DNA vaccine, is targeted to the endosomal/lysosomal compartment that contains class II MHC molecules and has been shown to be immunogenic in adult mice. Assuming that one such strategy could help to overcome the immunological immaturity in the early postnatal period, we have evaluated the systemic and mucosal immunogenicity of LAMP/gag immunization in neonatal mice. Intranasal immunization with LAMP/gag vaccine induced higher levels of sIgA and IgG anti-GAG antibodies in intestinal washes than did the gag vaccine. The combination of ID injections and the IN protocol with the chimeric vaccine promoted the increase of Ab levels in sera. Both vaccines induced splenic IFN-gamma- secreting cells against GAG peptide pools, as well as in vivo cytotoxic T lymphocyte (CTL) function, and increased the percentage of CD8+ T cells to the immunodominant class I peptide in gut and spleen. However, only the chimeric vaccine was able to enhance Th1/Th2 cytokine secretion in response to class II GAG peptide and to enhance IL-4-secreting cells against GAG peptides and p24 protein stimuli. Long-lasting humoral and cellular responses were detected until adult age, following neonatal immunization with the chimeric vaccine. The LAMP/gag vaccination was able to induce potent GAG-specific T and B cell immune responses in early life which are essential to elicit sustained and long-lasting mucosal and systemic humoral response. (C) 2010 Elsevier GmbH. All rights reserved.

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The immunogenicity and tolerability of virosome and of split influenza vaccines in patients with sickle cell anemia (SS) were evaluated Ninety SS patients from 8 to 34 years old were randomly assigned to receive either virosome (n = 43) or split vaccine (n = 47) Two blood samples were collected, one before and one 4-6 weeks after vaccination Antibodies against viral strains (2006) A/New Caledonia (H1N1), A/California (H3N2), B/Malaysia were determined using the hemagglutinin inhibition test Post-vaccine reactions were recorded over 7 days Seroconversion rates for HI NI, H3N2 and B were 65 1%. 60 4% and 83 7% for virosome vaccine, and 68 0%, 61 7% and 68 0% for split vaccine Seroprotection rates for HI NI, H3N2 e B were 100%. 97 6% and 69.7% for virosome. and 97 8%, 97 8% and 76 6% for split vaccine No severe adverse reactions were recorded Virosome and split vaccines in patients with sickle cell anemia were equally Immunogenic. with high seroconversion and seroprotection rates Both vaccines were well tolerated (C) 2009 Elsevier Ltd All rights reserved

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Group C rotavirus (GpCRV) has a worldwide distribution; however, its epidemiology and ecology are still unclear. Evidence for a possible zoonotic role has been postulated recently for Brazilian children strains. The aim of this study was to monitor GpCRV in children <= 15 years with acute gastroenteritis during the 2007-2010 national Brazilian rotavirus surveillance, and to undertake the molecular characterization of the major VP6 capsid protein. A total of 3,019 fecal samples were first screened for Group A rotavirus (GpARV). A total of 2,205 GpARV ELISA negative samples were tested further for the presence of GpCRV by SDS-PAGE, electronic microscopy, and RT-PCR for the VP6 gene. The genetic diversity of GpCRV was carried out by sequencing the VP6 gene. GpARV and GpCRV infections were detected in 24.6% (742/3,019) and 0.3% (8/3,019), respectively. The GpCRV detection rate increased from 0.2% (1/422) in 2007 to 1% (7/708) in 2008, and GpCRV cases were not detected in 2009 and 2010. The phylogenetic analysis indicated that the strains belonged to the human lineage, and showed a genetic relationship with the GpCRV strain from Japan isolated in 2009. None of the study sequences was related closely to animal GpCRV strains. This study provides further evidence that GpCRV is a minor cause of acute childhood gastroenteritis in Brazil, and does not suggest that GpCRV may assume epidemiological importance in the future, even after the introduction of a GpARV vaccine. In addition, the molecular analyses of the GpCRV samples in this study do not support the zoonotic hypothesis. J. Med. Virol. 83: 1631-1636, 2011. (C) 2011 Wiley-Liss, Inc.

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Introduction: Two hundred ten patients with newly diagnosed Hodgkin`s lymphoma (HL) were consecutively enrolled in this prospective trial to evaluate the cost-effectiveness of fluorine-18 ((18)F)-fluoro-2-deoxy-D-glucose-positron emission tomography (FDG-PET) scan in initial staging of patients with HL. Methods: All 210 patients were staged with conventional clinical staging (CCS) methods, including computed tomography (CT), bone marrow biopsy (BMB), and laboratory tests. Patients were also submitted to metabolic staging (MS) with whole-body FDG-PET scan before the beginning of treatment. A standard of reference for staging was determined with all staging procedures, histologic examination, and follow-up examinations. The accuracy of the CCS was compared with the MS. Local unit costs of procedures and tests were evaluated. Incremental cost-effectiveness ratio (ICER) was calculated for both strategies. Results: In the 210 patients with HL, the sensitivity for initial staging of FDG-PET was higher than that of CT and BMB in initial staging (97.9% vs. 87.3%; P < .001 and 94.2% vs. 71.4%, P < 0.003, respectively). The incorporation of FDG-PET in the staging procedure upstaged disease in 50 (24%) patients and downstaged disease in 17 (8%) patients. Changes in treatment would be seen in 32 (15%) patients. Cumulative cost for staging procedures was $3751/patient for CCS compared to $5081 for CCS + PET and $4588 for PET/CT. The ICER of PET/CT strategy was $16,215 per patient with modified treatment. PET/CT costs at the beginning and end of treatment would increase total costs of HL staging and first-line treatment by only 2%. Conclusion: FDG-PET is more accurate than CT and BMB in HL staging. Given observed probabilities, FDG-PET is highly cost-effective in the public health care program in Brazil.

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Purpose To assess the cost effectiveness of fluorine-18-fluorodeoxyglucose positron emission tomography (FDG-PET) in patients with Hodgkin`s lymphoma (HL) with unconfirmed complete remission (CRu) or partial remission (PR) after first-line treatment. Patients and Methods One hundred thirty patients with HL were prospectively studied. After treatment, all patients with CRu/PR were evaluated with FDG-PET. In addition, PET-negative patients were evaluated with standard follow-up, and PET-positive patients were evaluated with biopsies of the positive lesions. Local unit costs of procedures and tests were evaluated. Cost effectiveness was determined by evaluating projected annual economic impact of strategies without and with FDG-PET on HL management. Results After treatment, CRu/PR was observed in 50 (40.0%) of the 127 patients; the sensitivity, specificity, and positive and negative predictive values of FDG-PET were 100%, 92.0%, 92.3%, and 100%, respectively (accuracy of 95.9%). Local restaging costs without PET were $350,050 compared with $283,262 with PET, a 19% decrease. The incremental cost-effectiveness ratio is -$3,268 to detect one true case. PET costs represented 1% of total costs of HL treatment. Simulated costs in the 974 patients registered in the 2008 Brazilian public health care database showed that the strategy including restaging PET would have a total program cost of $56,498,314, which is $516,942 less than without restaging PET, resulting in a 1% cost saving. Conclusion FDG-PET demonstrated 95.9% accuracy in restaging for patients with HL with CRu/PR after first-line therapy. Given the observed probabilities, FDG-PET is highly cost effective and would reduce costs for the public health care program in Brazil.