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Polysaccharide Vaccine (polysaccharide + vaccine)
Selected AbstractsRecommendations for immunizations in stem cell transplantationPEDIATRIC TRANSPLANTATION, Issue 2003Deborah C. Molrine Abstract: Investigations over the past decade have documented that there is a decline in immunity to vaccine preventable diseases in many SCT recipients. The majority of immunization studies conducted in SCT recipients to date support the use of multi-dose regimens for most protein and polysaccharide-conjugate vaccine antigens. The consensus immunization schedule recommended by ACIP/IDSA/ASBMT provides guidance for centers to utilize available vaccines in their SCT populations. With the exception of pneumococcal disease, a schedule beginning at 12 months after SCT is reasonable given the low incidence of disease in HSCT recipients for most of the recommended vaccines and improved immune reconstitution in most recipients by one year post transplant. SCT recipients respond poorly to unconjugated pneumococcal polysaccharide vaccine and the development of polysaccharide-protein conjugate vaccines against S. pneumoniae holds promise to impact potentially on clinical disease in this population. In addition, the strategy of donor immunization may also be effective in eliciting early protective immune responses to vaccine antigens. Future challenges will be the development of safe and effective vaccines against the viral pathogens responsible for considerable morbidity and mortality after SCT. [source] Immunization responses in rheumatoid arthritis patients treated with rituximab: Results from a controlled clinical trial,ARTHRITIS & RHEUMATISM, Issue 1 2010Clifton O. Bingham III Objective To examine immunization responses in patients with rheumatoid arthritis (RA) treated with rituximab and to investigate the effects of rituximab-induced CD20+ B cell depletion on immune responses to tetanus toxoid (T cell,dependent antigen), pneumococcal polysaccharide (T cell,independent antigen), and keyhole limpet hemocyanin (KLH) (neoantigen) and on delayed-type hypersensitivity (DTH). Methods In a controlled trial, we enrolled 103 patients with active RA receiving a stable dose of methotrexate (MTX). Tetanus toxoid, pneumococcal polysaccharide, and KLH vaccines as well as a Candida albicans skin test were administered to 1 group of patients receiving rituximab plus MTX (called rituximab-treated patients) for 36 weeks and to 1 group of patients receiving MTX alone for 12 weeks. The primary end point was the proportion of patients with a ,4-fold rise in antitetanus IgG levels. Antitetanus, antipneumococcal, and anti-KLH serum IgG levels were measured prior to and 4 weeks following vaccine administration. The DTH response to C albicans was measured 2,3 days following placement. Results Responses to tetanus toxoid vaccine (,4-fold rise) were similar in both groups (39.1% of rituximab-treated patients and 42.3% of patients treated with MTX alone). The ability to maintain a positive DTH response to the C albicans skin test was comparable in both groups (77.4% of rituximab-treated patients and 70% of patients treated with MTX alone), showing no effect of rituximab treatment. Rituximab-treated patients had decreased responses to pneumococcal polysaccharide vaccine (57% of patients had a 2-fold rise in titer in response to ,1 serotype, compared with 82% of patients treated with MTX alone) and to KLH vaccine (47% of patients had detectable anti-KLH IgG, compared with 93% of patients treated with MTX alone). Conclusion Recall responses to the T cell,dependent protein antigen tetanus toxoid as well as DTH responses were preserved in rituximab-treated RA patients 24 weeks after treatment. Responses to neoantigen (KLH) and T cell,independent responses to pneumococcal vaccine were decreased, but many patients were able to mount responses. These data suggest that polysaccharide and primary immunizations should be administered prior to rituximab infusions to maximize responses. [source] Mode of splenectomy and immunogenicity of meningococcal vaccination in patients with hereditary spherocytosis,BRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 4 2008G. A. Stoehr Background: Splenectomy predisposes patients to invasive disease from pneumococci, meningococci, and Haemophilus influenzae; immunization is mandatory. However, data on the impact of the splenectomy on vaccine immunogenicity are scarce. Methods: A total of 41 children with hereditary spherocytosis (aged 5·8,14·4 years) had complete (16) or near-total (25) splenectomy. All received one dose of monovalent meningococcal C conjugate vaccine (MCV-C) and, 2 months later, a tetravalent meningococcal polysaccharide vaccine (MPV-ACWY). Serum bactericidal activity and antibodies against serogroups A and C were determined before and after they received MCV-C, and 4 weeks after they received MPV-ACWY. Results: Before vaccination, only four of the 16 children who had a complete splenectomy were protected against serogroup A, compared with 15 of the 25 who had near-total splenectomy (P < 0·050), with the latter responding to immunization with significantly higher serogroup A serum bactericidal activity: geometric mean (95 per cent confidence interval) 1625.5 (49.9 to 3201.1) versus 980.6 (2.00 to 6204.1) (P < 0·050). All patients achieved putative protective serum bactericidal activity titres (at least 8) against serogroup C. Conclusion: Near-total splenectomy provides a favourable immunological basis for natural and vaccine-induced protection against meningococcal serogroup A and C infections. Sequential meningococcal vaccination is immunogenic in patients splenectomized for hereditary spherocytosis. Copyright © 2007 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd. [source] Invasive Streptococcus pneumoniae from Portugal: implications for vaccination and antimicrobial therapyCLINICAL MICROBIOLOGY AND INFECTION, Issue 7 2004I. Serrano Abstract The distribution of pneumococcal serotypes among 465 invasive isolates recovered from 1999 to 2002 in Portugal was analysed by age group. Serotype 14 was either the most prevalent or the second most prevalent in all age groups. Among children aged <,2 years, serotypes 6B and 23F, which are usually associated with children, together with serotypes 19A and 14, accounted for more than half of the isolates. In contrast, in older adults (, 60 years), serotypes 3, 14, 1, 8 and 4 were the most prevalent. The potential coverage of the seven-valent conjugate vaccine is 63.2% among infants, and does not change significantly if children aged <,6 years are considered, which is a lower coverage than in other European countries. The potential coverage of the 23-valent polysaccharide vaccine is high in all age groups, particularly among older adults (80.7%). All isolates were tested for their susceptibility to penicillin, cefuroxime, cefotaxime, vancomycin, erythromycin, clindamycin, levofloxacin, gatifloxacin, moxifloxacin, linezolid, quinupristin,dalfopristin, tetracycline, chloramphenicol and trimethoprim,sulphamethoxazole. Most isolates collected from children aged <,6 years had decreased susceptibility to at least one antibiotic class, whereas isolates from patients aged ,,6 years were mostly susceptible to all antimicrobial agents tested. Overall, 23% of isolates showed reduced susceptibility to penicillin. Most (98.5%) isolates remained fully susceptible to cefotaxime, and a single isolate was resistant to quinolones. [source] Novel vaccine strategies with protein antigens of Streptococcus pneumoniaeFEMS IMMUNOLOGY & MEDICAL MICROBIOLOGY, Issue 1 2003Edwin Swiatlo Abstract Infections caused by Streptococcus pneumoniae (pneumococcus) are a major cause of mortality throughout the world. This organism is primarily a commensal in the upper respiratory tract of humans, but can cause pneumonia in high-risk persons and disseminate from the lungs by invasion of the bloodstream. Currently, prevention of pneumococcal infections is by immunization with vaccines which contain capsular polysaccharides from the most common serotypes causing invasive disease. However, there are more than 90 antigenically distinct serotypes and there is concern that serotypes not included in the vaccines may become more prevalent in the face of continued use of polysaccharide vaccines. Also, certain high-risk groups have poor immunological responses to some of the polysaccharides in the vaccine formulations. Protein antigens that are conserved across all capsular serotypes would induce more effective and durable humoral immune responses and could potentially protect against all clinically relevant pneumococcal capsular types. This review provides a summary of work on pneumococcal proteins that are being investigated as components for future generations of improved pneumococcal vaccines. [source] | ||||||||||