Background: The media have played an important part in presenting arguments for and against vaccination. The potential for the media to influence public attitudes to vaccines is becoming increasingly crucial to address.
Methods: To understand the differing roles and responsibilities in the communication of vaccine trials we draw insight from a retrospective study of 349 survey responses and 102 semi-structured interviews conducted in 2020 with participants in the United Kingdom's first-in-human clinical trial of the Oxford-AstraZeneca COVID-19 vaccine.
Background: RH5 is a leading blood-stage candidate antigen for a Plasmodium falciparum vaccine; however, its safety and immunogenicity in malaria-endemic populations are unknown.
Methods: A phase 1b, single-center, dose-escalation, age-de-escalation, double-blind, randomized, controlled trial was conducted in Bagamoyo, Tanzania (NCT03435874). Between 12 April and 25 October 2018, 63 healthy adults (18-35 years), young children (1-6 years), and infants (6-11 months) received a priming dose of viral-vectored ChAd63 RH5 or rabies control vaccine.
Preclinical (animal) testing and human testing of drugs and vaccines are rarely considered by social scientists side by side. Where this is done, it is typically for theoretically exploring the ethics of the two situations to compare relative treatment. In contrast, we empirically explore how human clinical trial participants understand the role of animal test subjects in vaccine development.
View Article and Find Full Text PDFThere are no licensed vaccines against . We conducted two phase 1/2a clinical trials to assess two vaccines targeting Duffy-binding protein region II (PvDBPII). Recombinant viral vaccines using chimpanzee adenovirus 63 (ChAd63) and modified vaccinia virus Ankara (MVA) vectors as well as a protein and adjuvant formulation (PvDBPII/Matrix-M) were tested in both a standard and a delayed dosing regimen.
View Article and Find Full Text PDFIn early 2020, adult volunteers were invited to participate in a first-in-human trial of the COVID-19 vaccine, ChAdOx1 nCoV-19, in the United Kingdom (UK) at the height of the global pandemic when there was uncertainty regarding vaccine efficacy and side-effects. We conducted a retrospective survey of these uniquely situated individuals to gain insight into their views about the risks, motivations, and expectations of the trial and potential vaccine deployment. Our data from 349 respondents show that these volunteers were educated to a high-level with a clear understanding of the seriousness of the COVID-19 pandemic, as well as an appreciation of the role of science and research in developing a vaccine to address this global problem.
View Article and Find Full Text PDFObjective: To establish consensus definitions for necrotising otitis externa (NOE) to facilitate the diagnosis and exclusion of NOE in clinical practice and expedite future high-quality study of this neglected condition.
Design: The work comprised of a systematic review of the literature, five iterative rounds of consultation via a Delphi process and open discussion within the collaborative. An expert panel analysed the results to produce the final outputs which were shared with and endorsed by national specialty bodies.
Natural killer (NK) cells are potent immune effectors that can be activated via antibody-mediated Fc receptor engagement. Using multiparameter flow cytometry, we found that NK cells degranulate and release IFN-γ upon stimulation with antibody-opsonized merozoites. Antibody-dependent NK (Ab-NK) activity was largely strain transcending and enhanced invasion inhibition into erythrocytes.
View Article and Find Full Text PDFThe safety of novel therapeutics and vaccines are typically assessed in early phase clinical trials involving "healthy volunteers." Abnormalities in such individuals can be difficult to interpret and may indicate previously unrecognized medical conditions. The frequency of incidental findings (IFs) in healthy volunteers who attend for clinical trial screening is unclear.
View Article and Find Full Text PDFBackground: Vaccine nationalism has become a key topic of discussion during the development, testing, and rollout of COVID-19 vaccines. Media attention has highlighted the ways that global, coordinated access to vaccines has been limited during the pandemic. It has also exposed how some countries have secured vaccine supply, through bilateral purchase agreements and the way pharmaceutical companies have priced, negotiated, and delivered these supplies.
View Article and Find Full Text PDFBackground: A safe and efficacious vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), if deployed with high coverage, could contribute to the control of the COVID-19 pandemic. We evaluated the safety and efficacy of the ChAdOx1 nCoV-19 vaccine in a pooled interim analysis of four trials.
Methods: This analysis includes data from four ongoing blinded, randomised, controlled trials done across the UK, Brazil, and South Africa.
Background: Transcriptional profiling of the human immune response to malaria has been used to identify diagnostic markers, understand the pathogenicity of severe disease and dissect the mechanisms of naturally acquired immunity (NAI). However, interpreting this body of work is difficult given considerable variation in study design, definition of disease, patient selection and methodology employed. This work details a comprehensive review of gene expression profiling (GEP) of the human immune response to malaria to determine how this technology has been applied to date, instances where this has advanced understanding of NAI and the extent of variability in methodology between studies to allow informed comparison of data and interpretation of results.
View Article and Find Full Text PDFAim: This study quantified changes in the microbiology of osteomyelitis over a ten year period from a single centre within the UK with regard to infection with multi-drug resistant (MDR) bacteria and susceptibility of antimicrobial regimens.
Method: Patients with chronic osteomyelitis undergoing definitive surgery from 2013-2017 were inluded (n = 223). Microbiology was compared to patients in a cohort from 2001-2004, using the same diagnostic criteria, and same deep tissue sampling technique (n = 157).
Background: Heterologous prime boost immunization with chimpanzee adenovirus 63 (ChAd63) and Modified Vaccinia Virus Ankara (MVA) vectored vaccines is a strategy previously shown to provide substantial protective efficacy against P. falciparum infection in United Kingdom adult Phase IIa sporozoite challenge studies (approximately 20-25% sterile protection with similar numbers showing clear delay in time to patency), and greater point efficacy in a trial in Kenyan adults.
Methodology: We conducted the first Phase IIb clinical trial assessing the safety, immunogenicity and efficacy of ChAd63 MVA ME-TRAP in 700 healthy malaria exposed children aged 5-17 months in a highly endemic malaria transmission area of Burkina Faso.
Epidemiological observations have linked increased host iron with malaria susceptibility, and perturbed iron handling has been hypothesized to contribute to the potentially life-threatening anemia that may accompany blood-stage malaria infection. To improve our understanding of these relationships, we examined the pathways involved in regulation of the master controller of iron metabolism, the hormone hepcidin, in malaria infection. We show that hepcidin upregulation in murine malaria infection was accompanied by changes in expression of bone morphogenetic protein (BMP)/sons of mothers against decapentaplegic (SMAD) pathway target genes, a key pathway involved in hepcidin regulation.
View Article and Find Full Text PDFBackground: The PfEMP1 family of Plasmodium falciparum antigens play a key role in pathogenesis of severe malaria through their insertion into the surface of parasite infected erythrocytes, and adhesion to host cells. Previous studies have suggested that parasites expressing PfEMP1 subclasses group A and DC8, associated with severe malaria, may have a growth advantage in immunologically naïve individuals. However, this idea has not been tested in longitudinal studies.
View Article and Find Full Text PDFHeterologous prime-boosting with viral vectors encoding the pre-erythrocytic antigen thrombospondin-related adhesion protein fused to a multiple epitope string (ME-TRAP) induces CD8 T cell-mediated immunity to malaria sporozoite challenge in European malaria-naive and Kenyan semi-immune adults. This approach has yet to be evaluated in children and infants. We assessed this vaccine strategy among 138 Gambian and Burkinabe children in four cohorts: 2- to 6-year olds in The Gambia, 5- to 17-month-olds in Burkina Faso, and 5- to 12-month-olds and 10-week-olds in The Gambia.
View Article and Find Full Text PDFEfforts are under way to improve the efficacy of subunit malaria vaccines through assessments of new adjuvants, vaccination platforms, and antigens. In this study, we further assessed the antigen upregulated in infective sporozoites 3 (PfUIS3) as a vaccine candidate. PfUIS3 was expressed in the viral vectors chimpanzee adenovirus 63 (ChAd63) and modified vaccinia virus Ankara (MVA) and used to immunize mice in a prime-boost regimen.
View Article and Find Full Text PDFThe timing of infection is closely determined in controlled human malaria infection (CHMI) studies, and as such they provide a unique opportunity to dissect changes in immunological responses before and after a single infection. The first Kenyan Challenge Study (KCS) (Pan African Clinical Trial Registry: PACTR20121100033272) was performed in 2013 with the aim of establishing the CHMI model in Kenya. This study used aseptic, cryopreserved, attenuated sporozoites administered by needle and syringe (PfSPZ Challenge) and was the first to evaluate parasite dynamics post-CHMI in individuals with varying degrees of prior exposure to malaria.
View Article and Find Full Text PDFMalaria remains a significant global health burden and a vaccine would make a substantial contribution to malaria control. Chimpanzee Adenovirus 63 Modified Vaccinia Ankara Multiple epitope thrombospondin adhesion protein (ME-TRAP) and vaccination has shown significant efficacy against malaria sporozoite challenge in malaria-naive European volunteers and against malaria infection in Kenyan adults. Infants are the target age group for malaria vaccination; however, no studies have yet assessed T-cell responses in children and infants.
View Article and Find Full Text PDFIntroduction: Severe malaria mainly affects children aged under 5 years, non-immune travellers, migrants to malarial areas, and people living in areas with unstable or seasonal malaria. Cerebral malaria, causing encephalopathy and coma, is fatal in around 20% of children and adults, and may lead to neurological sequelae in survivors. Severe malarial anaemia may have a mortality rate of over 13%.
View Article and Find Full Text PDFBackground: Models of controlled human malaria infection (CHMI) initiated by mosquito bite have been widely used to assess efficacy of preerythrocytic vaccine candidates in small proof-of-concept phase 2a clinical trials. Efficacy testing of blood-stage malaria parasite vaccines, however, has generally relied on larger-scale phase 2b field trials in malaria-endemic populations. We report the use of a blood-stage P.
View Article and Find Full Text PDFThe assessment of naturally-acquired and vaccine-induced immunity to blood-stage Plasmodium falciparum malaria is of long-standing interest. However, the field has suffered from a paucity of in vitro assays that reproducibly measure the anti-parasitic activity induced by antibodies in conjunction with immune cells. Here we optimize the antibody-dependent respiratory burst (ADRB) assay, which assesses the ability of antibodies to activate the release of reactive oxygen species from human neutrophils in response to P.
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