Alternative vaccine delivery methods
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PROVIDER: S-EPMC7151876 | biostudies-literature | 2012 Nov
REPOSITORIES: biostudies-literature
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Project description:Vaccines are recognized worldwide as one of the most important tools for combating infectious diseases. Despite the tremendous value conferred by currently available vaccines toward public health, the implementation of additional vaccine platforms is also of key importance. In fact, currently available vaccines possess shortcomings, such as inefficient triggering of a cell-mediated immune response and the lack of protective mucosal immunity. In this regard, recent work has been focused on vaccine delivery systems, as an alternative to injectable vaccines, to increase antigen stability and improve overall immunogenicity. In particular, novel strategies based on edible or intradermal vaccine formulations have been demonstrated to trigger both a systemic and mucosal immune response. These novel vaccination delivery systems offer several advantages over the injectable preparations including self-administration, reduced cost, stability, and elimination of a cold chain. In this review, the latest findings and accomplishments regarding edible and intradermal vaccines are described in the context of the system used for immunogen expression, their molecular features and capacity to induce a protective systemic and mucosal response.
| S-EPMC6425294 | biostudies-literature
Project description:BackgroundParents use alternative protective methods instead of having their children vaccinated because of their various concerns.AimsThe aim of this study is to examine the processes by which the parents preferred alternative methods rather than the vaccines to strengthen their child's immune system.MethodsSemi-structured, qualitative interviews were conducted with 22 parents who had vaccine hesitancy. The study sample consisted of parents whose children were between the ages of 0 and 18 years and who experienced vaccine hesitancy and lived in Turkey. The interviews with individuals were conducted online and aimed to be representative of the population of Turkey.ResultsThe factors that caused parental vaccine hesitancy were various, such as vaccine contents, distrust of healthcare workers and false information about vaccines. Because of these factors, parents resorted to natural nutrition, vitamin support and some other precautions, such as avoiding takeaway food or preparing homemade food, rather than having their children vaccinated.ConclusionsIn recent years, it is thought that parents need education about vaccination; outbreaks may be caused by immigrant children who cannot be registered, and therefore cannot be vaccinated, in Turkey, which has received immigration at a high rate.
| S-EPMC8899307 | biostudies-literature
Project description:Powder-injectors use gas propulsion to deposit lyophilised drug or vaccine particles in the epidermal and sub epidermal layers of the skin. We prepared dry-powder (Tg = 45.2 ± 0.5°C) microparticles (58.1 μm) of a MenY-CRM197 glyconjugate vaccine (0.5% wt.) for intradermal needle-free powder injection (NFPI). SFD used ultrasound atomisation of the liquid vaccine-containing excipient feed, followed by lyophilisation above the glass transition temperature (Tg' = - 29.9 ± 0.3°C). This resulted in robust particles (density~ 0.53 ±0.09 g/cm3) with a narrow volume size distribution (mean diameter 58.1 μm, and span = 1.2), and an impact parameter (ρvr ~ 11.5 kg/m·s) sufficient to breach the Stratum corneum (sc). The trehalose, manitol, dextran (10 kDa), dextran (150 kDa) formulation, or TMDD (3:3:3:1), protected the MenY-CRM197 glyconjugate during SFD with minimal loss, no detectable chemical degradation or physical aggregation. In a capsular group Y Neisseria meningitidis serum bactericidal assay (SBA) with human serum complement, the needle free vaccine, which contained no alum adjuvant, induced functional protective antibody responses in vivo of similar magnitude to the conventional vaccine injected by hypodermic needle and syringe and containing alum adjuvant. These results demonstrate that needle-free vaccination is both technically and immunologically valid, and could be considered for vaccines in development.
| S-EPMC5570268 | biostudies-literature
Project description:Compared with conventional intravenous platinum and taxane-based chemotherapy for ovarian cancer, both intraperitoneal chemotherapy and more frequent dose-dense intravenous chemotherapy have been associated with improved survival in some studies. We examined the utilization and toxicity of these three methods of chemotherapy delivery in women with ovarian cancer.We performed a population-based study and analyzed data on women with ovarian cancer who underwent primary surgery followed by platinum and taxane-based chemotherapy from 2009 to 2013 who were recorded in the MarketScan database. Adjuvant chemotherapy was classified as: intraperitoneal chemotherapy, dose-dense chemotherapy (weekly administration of chemotherapy), or standard chemotherapy (every 3 weeks). Hospitalizations and emergency department visits for chemotherapy-associated complications and costs were recorded and compared using ? tests.A total of 5,892 patients, including 4,135 (70.2%) who received standard chemotherapy, 859 (14.6%) who received intraperitoneal chemotherapy, and 898 (15.2%) treated with dose-dense chemotherapy, were identified. From 2009 to 2013, use of intraperitoneal chemotherapy remained constant (16.3-16.3%), whereas use of dose-dense therapy increased (8.7-18.1%) (P<.001). Hospitalizations for chemotherapy-associated complications occurred in 21.3% of women receiving standard chemotherapy, 34.7% of patients treated with intraperitoneal therapy, and in 25.2% of those receiving dose-dense treatment (P<.001); emergency department visits occurred in 18.3%, 26.3%, and 20.3%, respectively (P<.001). The largest differences in hospitalizations and emergency department visits were seen for gastrointestinal toxicities and electrolyte disorders. The per-patient costs of hospitalization were higher for intraperitoneal chemotherapy than other treatment modalities.Intraperitoneal chemotherapy was used in less than 15% of women with ovarian cancer, whereas use of dose-dense chemotherapy is increasing. Although we did not examine survival, intraperitoneal chemotherapy is significantly more toxic than the other methods of treatment.
| S-EPMC4879086 | biostudies-literature
Project description:BackgroundDifferences in definitions and methodological approaches have hindered comparison and synthesis of economic evaluation results across multiple health domains, including immunization. At the request of the World Health Organization's (WHO) Immunization and Vaccines-related Implementation Research Advisory Committee (IVIR-AC), WHO convened an ad hoc Vaccine Delivery Costing Working Group, comprising experts from eight organizations working in immunization costing, to address a lack of standardization and gaps in definitions and methodological guidance. The aim of the Working Group was to develop a consensus statement harmonizing terminology and principles and to formulate recommendations for vaccine delivery costing for decision making. This paper discusses the process, findings of the review, and recommendations in the Consensus Statement.MethodsThe Working Group conducted several interviews, teleconferences, and one in-person meeting to identify groups working in vaccine delivery costing as well as existing guidance documents and costing tools, focusing on those for low- and middle-income country settings. They then reviewed the costing aims, perspectives, terms, methods, and principles in these documents. Consensus statement principles were drafted to align with the Global Health Cost Consortium costing guide as an agreed normative reference, and consensus definitions were drafted to reflect the predominant view across the documents reviewed.ResultsThe Working Group identified four major workstreams on vaccine delivery costing as well as nine guidance documents and eleven costing tools for immunization costing. They found that some terms and principles were commonly defined while others were specific to individual workstreams. Based on these findings and extensive consultation, recommendations to harmonize differences in terminology and principles were made.ConclusionsUse of standardized principles and definitions outlined in the Consensus Statement within the immunization delivery costing community of practice can facilitate interpretation of economic evidence by global, regional, and national decision makers. Improving methodological alignment and clarity in program costing of health services such as immunization is important to support evidence-based policies and optimal resource allocation. On the other hand, this review and Consensus Statement development process revealed the limitations of our ability to harmonize given that study designs will vary depending upon the policy question that is being addressed and the country context.
| S-EPMC8902809 | biostudies-literature
Project description:Vaccine immunogenicity and reactogenicity depend on recipient and vaccine characteristics. We hypothesized that healthy adults reporting higher reactogenicity from seasonal inactivated influenza vaccine (IIV) developed higher antibody titers compared with those reporting lower reactogenicity. We performed a secondary analysis of a randomized phase 1 trial of a trivalent IIV delivered by microneedle patch (MNP) or intramuscular (IM) injection. We created composite reactogenicity scores as exposure variables and used hemagglutination inhibition (HAI) titers as outcome variables. We used mixed-model analysis of variance to estimate geometric mean titers (GMTs) and titer fold change and modified Poisson generalized estimating equations to estimate risk ratios of seroprotection and seroconversion. Estimates of H3N2 GMTs were associated with the Systemic and Local scores among the IM group. Within the IM group, those with high reaction scores had lower baseline H3N2 GMTs and twice the titer fold change by day 28. Those with high Local scores had a greater probability of seroconversion. These results suggest that heightened reactogenicity to IM IIV is related to low baseline humoral immunity to an included antigen. Participants with greater reactogenicity developed greater titer fold change after 4 weeks, although the response magnitude was similar or lower compared with low-reactogenicity participants.
| S-EPMC11281354 | biostudies-literature
Project description:Bacterial vaginosis (BV) is one of the most common vaginal infections that affects hundreds of millions of women of reproductive age, worldwide. Traditional treatment strategies, such as oral and topical antibiotics, have shown efficacy against BV, but frequent recurrence of infection and the development of antibiotic-resistant bacteria remain as significant challenges. Alternatively, recent progress in understanding immune, microbiological, and metabolic interactions in the vaginal microbiota has prompted the consideration of administering probiotic organisms to restore and maintain vaginal health within the context of BV prevention and treatment. Given this, the objective of this review is to discuss existing and potential alternative approaches to deliver, and to potentially sustain the delivery of probiotics, to prevent and/or treat BV infections. First, a brief overview is provided regarding the probiotic species and combinatorial probiotic strategies that have shown promise in the treatment of BV and in restoring female reproductive health. Additionally, the advantages and challenges associated with current oral and intravaginal probiotic delivery platforms are discussed. Lastly, we present emerging and promising alternative dosage forms, such as electrospun fibers and 3D bioprinted scaffolds, that may be adapted as new strategies to intravaginally deliver probiotic organisms. Graphical abstract.
| S-EPMC8356663 | biostudies-literature
Project description:BACKGROUND:Global health partnerships have expanded exponentially in the last two decades with Gavi, the Vaccine Alliance considered the model's pioneer and leader because of its vaccination programs' implementation mechanism. Gavi, relies on diverse domestic and international partners to carry out the programs in low- and middle-income countries under a partnership engagement framework (PEF). In this study, we utilized mixed methods to examine Mozambique's Gavi driven partnership network which delivered human papillomavirus (HPV) vaccine during the demonstration phase. METHODS:Qualitative tools gauged contextual factors, prerequisites, partner performance and practices while a social network analysis (SNA) survey measured the partnership structure and perceived added value in terms of effectiveness, efficiency and country ownership. Forty key informants who were interviewed included frontline Ministry of Health workers, Ministry of Education staff and supporting partner organization members, of whom 34 participated in the social network analysis survey. RESULTS:Partnership structure SNA connectivity measurement scores of reachability (100%) and average distance (2.5), were high, revealing a network of very well-connected HPV vaccination implementation collaborators. Such high scores reflect a network structure favorable for rapid and widespread diffusion of information, features necessary for engaging and handling multiple implementation scales. High SNA effectiveness and efficiency measures for structural holes (85%) and low redundancy (30%) coupled with high mean perceived effectiveness (97.6%) and efficiency (79.5%) network outcome scores were observed. Additionally, the tie strength average score of 4.1 on a scale of 5 denoted high professional trust. These are all markers of a collaborative partnership environment in which disparate institutions and organizations leveraged each entity's comparative advantage. Lower perceived outcome scores for country ownership (24%) were found, with participants citing the prominent role of several out-of-country partner organizations as a major obstacle. CONCLUSIONS:While there is room for improvement on the country ownership aspects of the partnership, the expanded, diverse and inclusive collaboration of institutions and organizations that implemented the Mozambique HPV vaccine demonstration project was effective and efficient. We recommend that the country adapt a similar model during national scale up of HPV vaccination.
| S-EPMC7275554 | biostudies-literature
Project description:Gene editing following designer nuclease cleavage in the presence of a DNA donor template can revert mutations in disease-causing genes. For optimal benefit, reversion of the point mutation in HBB leading to sickle cell disease (SCD) would permit precise homology-directed repair (HDR) while concurrently limiting on-target non-homologous end joining (NHEJ)-based HBB disruption. In this study, we directly compared the relative efficiency of co-delivery of a novel CRISPR/Cas9 ribonucleoprotein targeting HBB in association with recombinant adeno-associated virus 6 (rAAV6) versus single-stranded oligodeoxynucleotides (ssODNs) to introduce the sickle mutation (GTC or GTG; encoding E6V) or a silent change (GAA; encoding E6optE) in human CD34+ mobilized peripheral blood stem cells (mPBSCs) derived from healthy donors. In vitro, rAAV6 outperformed ssODN donor template delivery and mediated greater HDR correction, leading to both higher HDR rates and a higher HDR:NHEJ ratio. In contrast, at 12-14 weeks post-transplant into recipient, immunodeficient, NOD, B6, SCID Il2rγ-/- Kit(W41/W41) (NBSGW) mice, a ∼6-fold higher proportion of ssODN-modified cells persisted in vivo compared to recipients of rAAV6-modified mPBSCs. Together, our findings highlight that methodology for donor template delivery markedly impacts long-term persistence of HBB gene-modified mPBSCs, and they suggest that the ssODN platform is likely to be most amenable to direct clinical translation.
| S-EPMC6611979 | biostudies-literature
Project description:Lipid-based vaccine delivery systems such as the conventional liposomes, virosomes, bilosomes, vesosomes, pH-fusogenic liposomes, transferosomes, immuno-liposomes, ethosomes, and lipid nanoparticles have gained a remarkable interest in vaccine delivery due to their ability to render antigens in vesicular structures, that in turn prevents its enzymatic degradation in vivo. The particulate form of lipid-based nanocarriers confers immunostimulatory potential, making them ideal antigen carriers. Facilitation in the uptake of antigen-loaded nanocarriers, by the antigen-presenting cells and its subsequent presentation through the major histocompatibility complex molecules, leads to the activation of a cascade of immune responses. Further, such nanocarriers can be tailored to achieve the desired characteristics such as charge, size, size distribution, entrapment, and site-specificity through modifications in the composition of lipids and the selection of the appropriate method of preparation. This ultimately adds to its versatility as an effective vaccine delivery carrier. The current review focuses on the various lipid-based carriers that have been investigated to date as potential vaccine delivery systems, the factors that affect their efficacy, and their various methods of preparation. The emerging trends in lipid-based mRNA vaccines and lipid-based DNA vaccines have also been summarized.
| S-EPMC10051624 | biostudies-literature