63 resultados para Immunization Programs
Resumo:
When the US Preventive Services Task Force (USPSTF) in 2009 recommended against universal breast cancer screening with mammography in women aged 40 to 49 years, some scientists, radiologists, politicians, and patients strongly objected. The controversy has been called the "mammography wars." The latest chapter in these wars comes from the Swiss Medical Board, which is mandated by the Conference of Health Ministers of the Swiss Cantons, the Swiss Medical Association, and the Swiss Academy of Medical Sciences to conduct health technology assessments. In a February 2014 report, the Swiss Medical Board stated that new systematic mammography screening programs should not be introduced, irrespective of the age of the women, and that existing programs should be discontinued. The board's main argument was that the absolute reduction in breast cancer mortality was low and that the adverse consequences of the screening were substantial. The absolute risk reduction in breast cancer mortality has been estimated by the board at 0.16% for women screened during 6.2 years and followed-up over 13 years, based on the results of a recent Cochrane Review. The adverse consequences include falsepositive test results, overdiagnosis and overtreatment of patients, and high costs, including the expense of follow-up testing and procedures.
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We have recently shown that nasal immunization of anesthetized mice with human papillomavirus type 16 (HPV16) virus-like particles (VLPs) is highly effective at inducing both neutralizing immunoglobulin A (IgA) and IgG in genital secretions, while parenteral immunization induced only neutralizing IgG. Our data also demonstrated that both isotypes are similarly neutralizing according to an in vitro pseudotyped neutralization assay. However, it is known that various amounts of IgA and IgG are produced in genital secretions along the estrous cycle. Therefore, we have investigated how this variation influences the amount of HPV16 neutralizing antibodies induced after immunization with VLPs. We have compared parenteral and nasal protocols of vaccination with daily samplings of genital secretions of mice. Enzyme-linked immunosorbent assay analysis showed that total IgA and IgG inversely varied along the estrous cycle, with the largest amounts of IgA in proestrus-estrus and the largest amount of IgG in diestrus. This resulted in HPV16 neutralizing titers of IgG only being achieved during diestrus upon parenteral immunization. In contrast, nasal vaccination induced neutralizing titers of IgA plus IgG throughout the estrous cycle, as confirmed by in vitro pseudotyped neutralization assays. Our data suggest that mucosal immunization might be more efficient than parenteral immunization at inducing continuous protection of the female genital tract.
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While the morphological and electrophysiological changes underlying diabetic peripheral neuropathy (DPN) are relatively well described, the involved molecular mechanisms remain poorly understood. In this study, we investigated whether phenotypic changes associated with early DPN are correlated with transcriptional alterations in the neuronal (dorsal root ganglia [DRG]) or the glial (endoneurium) compartments of the peripheral nerve. We used Ins2(Akita/+) mice to study transcriptional changes underlying the onset of DPN in type 1 diabetes mellitus (DM). Weight, blood glucose and motor nerve conduction velocity (MNCV) were measured in Ins2(Akita/+) and control mice during the first three months of life in order to determine the onset of DPN. Based on this phenotypic characterization, we performed gene expression profiling using sciatic nerve endoneurium and DRG isolated from pre-symptomatic and early symptomatic Ins2(Akita/+) mice and sex-matched littermate controls. Our phenotypic analysis of Ins2(Akita/+) mice revealed that DPN, as measured by reduced MNCV, is detectable in affected animals already one week after the onset of hyperglycemia. Surprisingly, the onset of DPN was not associated with any major persistent changes in gene expression profiles in either sciatic nerve endoneurium or DRG. Our data thus demonstrated that the transcriptional programs in both endoneurial and neuronal compartments of the peripheral nerve are relatively resistant to the onset of hyperglycemia and hypoinsulinemia suggesting that either minor transcriptional alterations or changes on the proteomic level are responsible for the functional deficits associated with the onset of DPN in type 1 DM.
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Little is known about the maternal transfer of antibodies in natural host-parasite systems despite its possible evolutionary and ecological implications. In domestic animals, the maternal transfer of antibodies can enhance offspring survival via a temporary protection against parasites, but it can also interfere with the juvenile immune response to antigens. We tested the functional role of maternal antibodies in a natural population of a long-lived colonial seabird, the kittiwake (Rissa tridactyla), using a vaccine (Newcastle disease virus vaccine) to mimic parasite exposure combined with a cross-fostering design. We first investigated the role of prior maternal exposure on the interannual transmission of Ab to juveniles. We then tested the effect of these antibodies on the juvenile immune response to the same antigen. The results show that specific maternal antibodies were transferred to chicks 1 year after maternal exposure and that these antibodies were functional, i.e. they affected juvenile immunity. These results suggest that the role of maternal antibodies may depend on the timing and pattern of offspring exposure to parasites, along with the patterns of maternal exposure and the dynamics of her immune response. Overall, our approach underlines that although the transgenerational transfer of antibodies in natural populations is likely to have broad implications, the nature of these effects may vary dramatically among host-parasite systems, depending on the physiological mechanisms involved and the ecological context.
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INITIO is an open-labelled randomized trial evaluating first-line therapeutic strategies for human immunodeficiency virus-1 (HIV-1) infection. In an immunology substudy a tetanus toxoid booster (TTB) immunization was planned for 24 weeks after initiation of highly active antiretroviral therapy (HAART). All patients had received tetanus toxoid immunization in childhood. Generation of proliferative responses to tetanus toxoid was compared in two groups of patients, those receiving a protease inhibitor (PI)-sparing regimen (n = 21) and those receiving a PI-containing (n = 54) regimen. Fifty-two participants received a TTB immunization [PI-sparing (n = 15), PI-containing (n = 37)] and 23 participants did not [PI-sparing (n = 6) or PI-containing (n = 17)]. Cellular responses to tetanus antigen were monitored by lymphoproliferation at time of immunization and every 24 weeks to week 156. Proportions with a positive response (defined as stimulation index > or = 3 and Delta counts per minute > or = 3000) were compared at weeks 96 and 156. All analyses were intent-to-treat. Fifty-two participants had a TTB immunization at median 25 weeks; 23 patients did not. At weeks 96 and 156 there was no evidence of a difference in tetanus-specific responses, between those with or without TTB immunization (P = 0.2, P = 0.4). There was no difference in the proportion with response between those with PI-sparing or PI-containing regimens at both time-points (P = 0.8, P = 0.7). The proliferative response to tetanus toxoid was unaffected by initial HAART regimen. Anti-tetanus responses appear to reconstitute eventually in most patients over 156 weeks when treated successfully with HAART, irrespective of whether or not a TTB immunization has been administered.
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Expression of the cancer/germ-line antigen NY-ESO-1 by tumors elicits spontaneous humoral and cellular immune responses in some cancer patients. Development of vaccines capable of stimulating such comprehensive immune responses is desirable. We have produced recombinant lentivectors directing the intracellular synthesis of NY-ESO-1 (rLV/ESO) and have analyzed the in vivo immune response elicited by this vector. Single injection of rLV/ESO into HLA-A2-transgenic mice elicited long-lasting B and T cell responses against NY-ESO-1. CD8+ T cells against the HLA-A2-restricted peptide NY-ESO-1(157-165) were readily detectable ex vivo and showed restricted TCR Vbeta usage. Moreover, rLV/ESO elicited a far greater anti-NY-ESO-1(157-165) CD8+ T cell response than peptide- or protein-based vaccines. Anti-NY-ESO-1 antibodies were rapidly induced after immunization and their detection preceded that of the antigen-specific CD8+ T cells. The rLV/ESO also induced CD4+ T cells. These cells played an essential role as their depletion completely abrogated B cell and CD8+ T cell responses against NY-ESO-1. The induced CD4+ T cells were primarily directed against a single NY-ESO-1 epitope spanning amino acids 81-100. Altogether, our study shows that rLV/ESO induces potent and comprehensive immune responses in vivo.
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Aluminum-adsorbed hepatitis A vaccines are known to be highly efficient. We present here the case of a patient who was immunized against hepatitis A before leaving for Kenya and who contracted an acute symptomatic hepatitis A during travel.
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Thirty-five HLA-A2(+) patients with completely resected stage I-III melanoma were vaccinated multiple times over 6 months with a modified melanoma peptide, gp100(209-2M), emulsified in Montanide adjuvant. Direct ex vivo gp100(209-2M) tetramer analysis of pre- and postvaccine peripheral blood mononuclear cells (PBMCs) demonstrated significant increases in the frequency of tetramer(+) CD8(+) T cells after immunization for 33 of 35 evaluable patients (median, 0.36%; range, 0.05-8.9%). Ex vivo IFN-gamma cytokine flow cytometry analysis of postvaccine PBMCs after brief gp100(209-2M) in vitro activation showed that for all of the patients studied tetramer(+) CD8(+) T cells produced IFN-gamma; however, some patients had significant numbers of tetramer(+) IFN-gamma(-) CD8(+)T cells suggesting functional anergy. Additionally, 8 day gp100(209-2M) in vitro stimulation (IVS) of pre- and postvaccine PBMCs resulted in significant expansion of tetramer(+) CD8(+) T cells from postvaccine cells for 34 patients, and these IVS tetramer(+) CD8(+) T cells were functionally responsive by IFN-gamma cytokine flow cytometry analysis after restimulation with either native or modified gp100 peptide. However, correlated functional and phenotype analysis of IVS-expanded postvaccine CD8(+) T cells demonstrated the proliferation of functionally anergic gp100(209-2M)- tetramer(+) CD8(+) T cells in several patients and also indicated interpatient variability of gp100(209-2M) stimulated T-cell proliferation. Flow cytometry analysis of cryopreserved postvaccine PBMCs from representative patients showed that the majority of tetramer(+) CD8+ T cells (78.1 +/- 4.2%) had either an "effector" (CD45 RA(+)/CCR7(-)) or an "effector-memory" phenotype (CD45RA(-)/CCR7(-)). Notably, analysis of PBMCs collected 12-24 months after vaccine therapy demonstrated the durable presence of gp100(209-2M)-specific memory CD8(+) T cells with high proliferation potential. Overall, this report demonstrates that after vaccination with a MHC class I-restricted melanoma peptide, resected nonmetastatic melanoma patients can mount a significant antigen-specific CD8(+) T-cell immune response with a functionally intact memory component. The data further support the combined use of tetramer binding and functional assays in correlated ex vivo and IVS settings as a standard for immunomonitoring of cancer vaccine patients.
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Each year, approximately five million people die worldwide from putatively vaccine-preventable mucosally transmitted diseases. With respect to mass vaccination campaigns, one strategy to cope with this formidable challenge is aerosol vaccine delivery, which offers potential safety, logistical, and cost-saving advantages over traditional vaccination routes. Additionally, aerosol vaccination may elicit pivotal mucosal immune responses that could contain or eliminate mucosally transmitted pathogens in a preventative or therapeutic vaccine context. In this current preclinical non-human primate investigation, we demonstrate the feasibility of aerosol vaccination with the recombinant poxvirus-based vaccine vectors NYVAC and MVA. Real-time in vivo scintigraphy experiments with radiolabeled, aerosol-administered NYVAC-C (Clade C, HIV-1 vaccine) and MVA-HPV vaccines revealed consistent mucosal delivery to the respiratory tract. Furthermore, aerosol delivery of the vaccines was safe, inducing no vaccine-associated pathology, in particular in the brain and lungs, and was immunogenic. Administration of a DNA-C/NYVAC-C prime/boost regime resulted in both systemic and anal-genital HIV-specific immune responses that were still detectable 5 months after immunization. Thus, aerosol vaccination with NYVAC and MVA vectored vaccines constitutes a tool for large-scale vaccine efforts against mucosally transmitted pathogens.
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We have studied the immunogenicity of Plasmodium falciparum circumsporozoite (CS) protein-derived synthetic polypeptides in mice. These synthetic peptides correspond to the N- and the C-terminal domains 22-125 and 289-390, respectively of the P. falciparum 7G8 isolate CS protein expressed on the sporozoite surface. They comprise what is believed to be the mature protein, except for the central repetitive B cell domain. BALB/c (H-2d) mice were immunized s.c. with 50 micrograms soluble CS polypeptides emulsified in IFA. After a single immunization, CS-specific helper and cytotoxic T lymphocytes (CTLs) could be obtained. The resultant CTLs obtained by in vitro restimulation of primed lymph node (LN) cells recognized H-2Kd target cells in the presence of short synthetic peptides defined in the present study. These epitopes are contained within the N- and C-terminal regions of the CS protein, and correspond to sequences 39-47 and 333-342. In addition, these CTLs can specifically lyse H-2d target cells transfected with the CS gene. These results suggest that, by immunization of mice with large soluble CS synthetic polypeptides in IFA, it is possible to obtain MHC class I-restricted T cell responses specific for the CS protein. This approach might be advantageous in the formulation of efficient malaria subunit vaccines.
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Training is a crucial tool for building the capacity necessary for prevention and control of cardiovascular diseases (CVDs) in developing countries. This paper summarizes some features of a 2-week workshop aimed at enabling local health professionals to initiate a comprehensive CVD prevention and control program in a context of limited resources. The workshops have been organized in the regions where CVD prevention programs are being contemplated, in cooperation with health authorities of the concerned regions. The workshop's content includes a broad variety of issues related to CVD prevention and control, and to program development. Strong emphasis is placed on "learning by doing," and groups of 5-6 participants conduct a small-scale epidemiological study during the first week; during the second week, they draft a virtual program of CVD prevention and control adapted to the local situation. This practice-oriented workshop focuses on building expertise among anticipated key players, strengthening networks among relevant health professionals, and advocating the urgent need to tackle the emerging CVD epidemic in developing countries.
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BACKGROUND: In Switzerland, intravenous drug use (IDU) accounts for 80% of newly acquired hepatitis C virus (HCV) infections. Early HCV treatment has the potential to interrupt the transmission chain and reduce morbidity/mortality due to decompensated liver cirrhosis and hepatocellular carcinoma. Nevertheless, patients in drug substitution programs are often insufficiently screened and treated. OBJECTIVE/METHODS: With the aim to improve HCV management in IDUs, we conducted a cross sectional chart review in three opioid substitution programs in St. Gallen (125 methadone and 71 heroin recipients). Results were compared with another heroin substitution program in Bern (202 patients) and SCCS/SHCS data. RESULTS: Among the methadone/heroin recipients in St. Gallen, diagnostic workup of HCV was better than expected: HCV/HIV-status was unknown in only 1% (2/196), HCV RNA was not performed in 9% (13/146) of anti-HCV-positives and the genotype missing in 15% (12/78) of HCV RNA-positives. In those without spontaneous clearance (two thirds), HCV treatment uptake was 23% (21/91) (HIV-: 29% (20/68), HIV+: 4% (1/23)), which was lower than in methadone/heroin recipients and particularly non-IDUs within the SCCS/SHCS, but higher than in the, mainly psychiatrically focussed, heroin substitution program in Bern (8%). Sustained virological response (SVR) rates were comparable in all settings (overall: 50%, genotype 1: 35-40%, genotype 3: two thirds). In St. Gallen, the median delay from the estimated date of infection (IDU start) to first diagnosis was 10 years and to treatment was another 7.5 years. CONCLUSIONS: Future efforts need to focus on earlier HCV diagnosis and improvement of treatment uptake among patients in drug substitution programs, particularly if patients are HIV-co-infected. New potent drugs might facilitate the decision to initiate treatment.
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Immunogenicity of a long 20-mer NY-ESO-1f peptide vaccine was evaluated in a lung cancer patient TK-f01, immunized with the peptide with Picibanil OK-432 and Montanide ISA-51. We showed that internalization of the peptide was necessary to present CD8 T-cell epitopes on APC, contrasting with the direct presentation of the short epitope. CD8 T-cell responses restricted to all five HLA class I alleles were induced in the patient after the peptide vaccination. Clonal analysis showed that B*35:01 and B*52:01-restricted CD8 T-cell responses were the two dominant responses. The minimal epitopes recognized by A*24:02, B*35:01, B*52:01 and C*12:02-restricted CD8 T-cell clones were defined and peptide/HLA tetramers were produced. NY-ESO-1 91-101 on A*24:02, NY-ESO-1 92-102 on B*35:01, NY-ESO-1 96-104 on B*52:01 and NY-ESO-1 96-104 on C*12:02 were new epitopes first defined in this study. Identification of the A*24:02 epitope is highly relevant for studying the Japanese population because of its high expression frequency (60%). High affinity CD8 T-cells recognizing tumor cells naturally expressing the epitopes and matched HLA were induced at a significant level. The findings suggest the usefulness of a long 20-mer NY-ESO-1f peptide harboring multiple CD8 T-cell epitopes as an NY-ESO-1 vaccine. Characterization of CD8 T-cell responses in immunomonitoring using peptide/HLA tetramers revealed that multiple CD8 T-cell responses comprised the dominant response.
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BACKGROUND & AIMS: Infection with Helicobacter induces a T helper type 1 response in mice and humans. Mice can be cured or protected from infection with Helicobacter by mucosal immunization with recombinant H. pylori urease B subunit (rUreB). This study characterizes the immune response of infected mice immunized with rUreB. METHODS: BALB/c mice were infected with H. felis. Two weeks later, they were orally immunized four times with rUreB and cholera toxin (CT) at weekly intervals. Controls were only infected or sham-immunized with CT. Animals were killed at various times after immunization. Splenic CD4(+) cells were obtained and cultured in vitro with rUreB to evaluate antigen-specific proliferation and induction of interferon gamma and interleukin 4 secretion. RESULTS: All rUreB-immunized mice (n = 8) were cured from infection 3 weeks after the fourth immunization. Immunization induced a proliferative response of splenic CD4(+) cells, a progressive decrease in interferon gamma secretion, and a concomitant increase in interleukin 4 secretion after each immunization. A simultaneous increase in rUreB specific serum immunoglobulin G1 levels was observed in infected/immunized mice. CONCLUSIONS: In BALB/c mice, therapeutic mucosal immunization with rUreB induces progressively a Th2 CD4(+) T cell response resulting in the elimination of the pathogen.