Vaccine
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The Decade of Vaccines Global Vaccine Action Plan has outlined a set of ambitious goals to broaden the impact and reach of immunization across the globe. A projections exercise has been undertaken to assess the costs, financing availability, and additional resource requirements to achieve these goals through the delivery of vaccines against 19 diseases across 94 low- and middle-income countries for the period 2011-2020. The exercise draws upon data from existing published and unpublished global forecasts, country immunization plans, and costing studies. ⋯ About 57% of the total resources required to close the funding gap are needed just to maintain existing programs and scale up other currently available vaccines (i.e., before adding in the additional costs of vaccines still in development). Efforts to mobilize additional resources, manage program costs, and establish mutual accountability between countries and development partners will all be necessary to ensure the goals of the Decade of Vaccines are achieved. Establishing or building on existing mechanisms to more comprehensively track resources and commitments for immunization will help facilitate these efforts.
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We aimed to determine demographic predictors of parental vaccine safety and risk perceptions, and assess the relationship between the occurrence of children's perceived adverse events following immunisation (AEFI) on parents' opinions. ⋯ Parents commonly perceive and report that their child has experienced an AEFI. In this group of parents the subsequent expectation of an AEFI and vaccine safety concerns may be heightened. Further research should investigate parental understandings of differentiating an expected event from an adverse event as this could inform immunization risk communication and consumer AEFI reporting strategies.
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The Global Alliance for Vaccines and Immunization (GAVI) is a public-private global health partnership aiming to increase access to immunisation in poor countries. The Democratic Republic of the Congo (DRC) is the third largest recipient of GAVI funds in terms of cumulative disbursed support. We provided a comprehensive assessment of GAVI support and analysed trends in immunisation performance and financing in the DRC from 2002 to 2010. ⋯ GAVI support to DRC has enhanced significant progress in routine immunisation performance and financing during 2002-2010. Although progress has been partly sustained, the initial observed increase in DTP3 coverage and available funding for routine immunisation halted towards the end of the analysis period, coinciding with tetravalent and pentavalent vaccine introduction. These findings highlight the need for additional efforts to ensure the sustainability of routine immunization program performance and financing.
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Epitopes of the circumsporozoite (CS) protein of Plasmodium falciparum, the most pathogenic species of the malaria parasite, have been shown to elicit protective immunity in experimental animals and human volunteers. The mechanisms of immunity include parasite-neutralizing antibodies that can inhibit parasite motility in the skin at the site of infection and in the bloodstream during transit to the hepatocyte host cell and also block interaction with host cell receptors on hepatocytes. In addition, specific CD4+ and CD8+ cellular mechanisms target the intracellular hepatic forms, thus preventing release of erythrocytic stage parasites from the infected hepatocyte and the ensuing blood stage cycle responsible for clinical disease. ⋯ In addition, mice immunized with microparticles bearing only T-cell epitopes were not protected, demonstrating that cellular immunity alone was not sufficient for protective immunity. Although the microparticles without adjuvant were immunogenic and protective, a simple modification with the lipopeptide TLR2 agonist Pam3Cys increased the potency and efficacy of the LbL vaccine candidate. This study demonstrates the potential of LbL particles as promising malaria vaccine candidates using the T1BT epitopes from the P. falciparum CS protein.
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Deterministic dynamic compartmental transmission models (DDCTMs) of human papillomavirus (HPV) transmission have been used in a number of studies to estimate the potential impact of HPV vaccination programs. In most cases, the models were built under the assumption that an individual who cleared HPV infection develops (life-long) natural immunity against re-infection with the same HPV type (this is known as SIR scenario). This assumption was also made by two Australian modelling studies evaluating the impact of the National HPV Vaccination Program to assist in the health-economic assessment of male vaccination. ⋯ We observed that for non-SIR models the herd immunity effect measured in relative reductions in HPV prevalence in the unvaccinated population was much more pronounced than for the SIR model. For example, with vaccine efficacy of 95% for females and 90% for males, the reductions for HPV-16 were 3% in females and 28% in males for the SIR model, and at least 30% (females) and 60% (males) for non-SIR models. The magnitude of these differences implies that evaluations of the impact of vaccination programs using DDCTMs should incorporate several model structures until our understanding of natural immunity is improved.