Vaccine
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Three independent, phase 1 clinical trials were conducted in Australia and in USA to assess the safety and immunogenicity of sanofi pasteur dengue vaccine candidates. In this context, Dengue 1-4 and Yellow Fever 17D-204 (YF 17D)-specific CD4 and CD8 cellular responses induced by tetravalent chimeric dengue vaccines (CYD) were analyzed in flavivirus-naive or flavivirus-immune patients. Tetravalent CYD vaccine did not trigger detectable changes in serum pro-inflammatory cytokines, whatever the vaccinees immune status, while inducing significant YF 17D NS3-specific CD8 responses and dengue serotype-specific T helper responses. ⋯ In all three trials, the profile of induced response was similar, whatever the subjects' immune status, i.e. an absence of Th2 response, and an IFN-gamma/TNF-alpha ratio dominated by IFN-gamma, for both CD4 and CD8 responses. Our results also showed an absence of cross-reactivity between YF 17D or Dengue NS3-specific CD8 responses, and allowed the identification of 3 new CD8 epitopes in the YF 17D NS3 antigen. These data are consistent with the previously demonstrated excellent safety of these dengue vaccines in flavivirus-naive and primed individuals.
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Vaccination of health care workers (HCW) in long-term care results in indirect protection of patients who are at high-risk for influenza. The voluntary uptake of influenza vaccination among HCW is generally low. ⋯ When uptake falls short a mandatory programme may be justified. The main justification stems from the duty of care givers not to harm one's patient when one knows there is a significant risk of harm and the intervention to reduce this chance has a favourable balance of benefit over burdens and risks.
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Pneumococcal disease and influenza are major causes of morbidity and mortality particularly among the elderly. Influenza and pneumococcal vaccination are recommended for people aged 65 years and older or persons with chronic illness. However, despite the burden of disease related to pneumococcus and influenza and the availability safe, efficacious and cost-effective vaccines, health care providers continue to have doubts about these vaccines. Little is known about barriers for pneumococcal vaccination in the health care providers particularly in the primary health care setting. Since 2005 a publicly funded program offering free pneumococcal vaccine for elderly people over 65 years has been implemented in Australia. ⋯ GPs and hospital health care workers in our study were aware of, agreed with, immunization recommendation for the pneumococcal vaccine. Physician barriers to vaccination were patient's refusals and competing priorities, particularly for hospital health care workers, who were less likely to see vaccination as a priority. Hospitalisation is an opportunity for vaccination, but utilisation of this opportunity is reduced by lack of access to information about immunization for hospital health care workers and competing priorities. These could be areas to target for improved uptake of the elderly immunization.
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In this study, recombinant virus-like particles (VLPs) were evaluated as a candidate vaccine against emerging influenza viruses with pandemic potential. The VLPs are composed of the hemagglutinin (HA), neuraminidase (NA), and matrix 1 (M1) proteins of the H5N1 A/Indonesia/05/2005 (clade 2.1; [Indo/05]) virus, which were expressed using baculovirus in Spodoptera frugiperda (Sf9) cells. Ferrets received either 2 injections of the VLP vaccine at escalating doses (based on HA content), recombinant HA, or were mock vaccinated. ⋯ Affinity of the anti-HA antibodies raised by the H5N1 Indo/05 VLPs had a higher association rate to the homologous clade 2.1 HA than to the clade 1 (VN/04) HA; however, once bound, antibodies had similar slow disassociation rates. These results provide support for continued development of the H5N1 VLPs as a candidate vaccine against pandemic influenza. Exploration of immunologic correlates of protection for H5N1 vaccines beyond HAI and neutralizing antibody responses is warranted.