View clinical trials related to Streptococcus Pneumoniae.
Filter by:Streptococcus pneumoniae is a gram-positive (GP) bacteria responsible for common infections such as community-acquired pneumonia (CAP), as well as complicated infections such as bacteremia, infective endocarditis and meningitis. S. pneumoniae bacteremia ranks among the top 10 most common pathogens associated with bloodstream infections and correlates with high morbidity and mortality worldwide.
The French Public Health Council recommended pneumococcal vaccination combined strategy for all immunocompromised patients in 2012. This strategy consisted in conjugated 13-valent pneumococcal injection followed 2 months later by polysaccharide 23-valent vaccine injection. General practitioners are usually in charge of this vaccination. Conjugated pneumococcal vaccine enhances the immunogenicity of the polysaccharide vaccine. Acute leukemia and lymphoma are treated with multiple courses of chemotherapy, impairing the immune system and potentially the response to vaccination. These patients are more at risk for developing pneumococcal invasive diseases than the general population. However, efficacy of pneumococcal vaccination is poorly documented in this setting. We assume that 70% of the patients are non-responders to vaccination, according to their anti-pneumococcal immunoglobulin G titers and the opsonophagocytic activity. To assess the immunogenicity of the pneumococcal vaccination combined strategy in adult population of acute leukemia and lymphoma, the investigator will measure anti-pneumococcal serotype-specific immunoglobulin G titers and opsonophagocytic activity at different time-points after completion of the combined vaccine strategy. The primary objective is to assess the immunogenicity of pneumococcal vaccination combined strategy at 3 months after the 13-valent pneumococcal injection (corresponding to 1 month after the end of the combined strategy) using immunoglobulin G titers and opsonophagocytic activity. At different time points (day 0, 1 month after the 13-valent pneumococcal injection, the day of the injection of the polysaccharide 23-valent vaccine, one month after the injection of the polysaccharide 23-valent vaccine, 3-6 months after the polysaccharide 23-valent vaccine,9-12 months after the polysaccharide 23-valent vaccine), the immunological response to vaccination will be monitored using specific-serotype immunoglobulin G titers, opsonophagocytic activity, and total anti-pneumococcal Immunoglobulin. The investigator will determine predictive factors of non-response to vaccination by comparing demographic data, biological data and treatment received by both acute myeloblastic leukemia and lymphoma patients. The tolerance and safety of the vaccination strategy will also be assessed in this specific hematological population.
Pneumococcal conjugate vaccines (PCV) have been shown to be effective against invasive pneumococcal disease (IPD; including pneumococcal meningitis and sepsis) and all-cause mortality among young children when introduced into infant expanded programs on immunization (EPI). Colonization of the nasopharynx by Streptococcus pneumoniae is a necessary prerequisite to pneumococcal disease. Critically important to the population impact of PCV is therefore reducing vaccine serotype (VT) carriage prevalence, and therefore reducing both disease and onward transmission to vulnerable individuals. Thus, as well as protecting the vaccinated individual (direct protection), PCV confers indirect protection (herd immunity) to unvaccinated populations and to vaccinated individuals who have insufficient protective immunity. While the ability of PCVs to induce herd immunity has been strong enough to control pneumococcal carriage in industrialized countries, such benefits have not been as marked in low-income countries. Carriage surveillance in Blantyre, Malawi from 4 to 7 years post-vaccine implementation shows persistent VT carriage. With the exception of South Africa, most sub-Saharan African countries, including Malawi, have introduced PCV using a 3+0 schedule. Whether the WHO-approved 2+1 schedule will maximize vaccine-induced protection has been identified as a research gap by the WHO. In this context, the Malawian Ministry of Health (MoH) and the National Immunizations Technical Advisory Committee (NITAG) are seeking evidence of adequate superiority of a 2+1 schedule to inform a change to the current Malawi EPI schedule. HYPOTHESIS: Prolonging the period of vaccine-induced protection with a booster vaccine dose at 9 months will extend the period of low VT carriage, hence providing longer direct vaccine-induced protection as well as boosting the indirect herd immunity effect. METHOD: The MoH will implement an evaluation, comparing a 2+1 to the current 3+0 PCV13 vaccine schedule in Blantyre District. This will use a pragmatic health centre-based randomization protocol, implemented within the scope of the EPI programme. This MoH-led change will be evaluated in partnership with the Malawi Liverpool Wellcome Trust Clinical Research Programme. Community carriage surveillance will be undertaken at 15 and 33 months after the introduction of the 2+1 schedule. The primary endpoint will be VT carriage prevalence among children 15-24 months of age 36 months after schedule change. Other targeted study groups will include children aged 5-10 years who have received PCV13 on a 3+0 schedule, children aged 9 months who have received PCV13 in either a 3+0 or a 2+0 schedule, and HIV-infected adults aged 18-40 years receiving ART and PCV13-unvaccinated. EXPECTED FINDINGS: Data will inform NITAG decisions on national vaccine policy, with implications at a national, regional and global level.
Objective: PCV effects on S. pneumoniae and S. aureus carriage in a population based study. The major specific aims: 1. To compare different PCV vaccination policies, by cross-sectional repeated surveillance of closely related populations living in regions with different vaccination policies. 2. To compare the epidemiology, predictors and outcomes of antibiotic resistant S. aureus and S. pneumoniae in different regions of the PICR. Study design: Annual / Biannual cross-sectional surveillance of nasal S. aureus carriage and nasopharyngeal S. pneumoniae carriage in children and one of their parents.