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The Oxford Vaccine Group is an independent multi-disciplinary clinical trials and epidemiology group based at the Centre for Clinical Vaccinology and Tropical Medicine, University of Oxford. OVG works towards the goal of developing new and improved vaccines for the prevention of infection in adults and children.
Complementary and alternative medicine: Do physicians believe they can meet the requirements of the Collège des médecins du Québec?
OBJECTIVE: To determine whether medical training prepares FPs to meet the requirements of the Collège des médecins du Québec for their role in advising patients on the use of complementary and alternative medicine (CAM). DESIGN: Secondary analysis of survey results. SETTING: Quebec. PARTICIPANTS: Family physicians and GPs in active practice. MAIN OUTCOME MEASURES: Perceptions of the role of the physician as an advisor on CAM; level of comfort responding to questions and advising patients on CAM; frequency with which patients ask their physicians about CAM; personal position on CAM; and desire for training on CAM. RESULTS: The response rate was 19.5% (195 respondents of 1000) and the sample appears to be representative of the target population. Most respondents (85.8%) reported being asked about CAM several times a month. A similar proportion (86.7%) believed it was their role to advise patients on CAM. However, of this group, only 33.1% reported being able to do so. There is an association between an urban practice and knowledge of the advisory role of physicians. More than three-quarters of respondents expressed interest in receiving additional training on CAM. CONCLUSION: There is a gap between the training that Quebec physicians receive on CAM and their need to meet legal and ethical obligations designed to protect the public where CAM products and therapies are concerned. One solution might be more thorough training on CAM to help physicians meet the Collège des médecins du Québec requirements.
Influential drivers of the cost-effectiveness of respiratory syncytial virus vaccination in European older adults: a multi-country analysis
Background: We aimed to identify influential drivers of the cost-effectiveness of older adult respiratory syncytial virus (RSV) vaccination in Denmark, Finland, the Netherlands and Valencia-Spain. Methods: A static multi-cohort model was parameterised using country- and age-specific hospitalisations using three approaches: (A) the International Classification of Diseases (ICD)-coded hospitalisations, (B) laboratory RSV-confirmed hospitalisations and (C) time-series modelling (TSM). Plausible hypothetical RSV vaccine characteristics were derived from two protein subunit vaccines for adults aged ≥60 years. A full incremental analysis was conducted by comparing three RSV vaccination strategies: (1) in adults aged ≥60 years (“60y+”); (2) in adults aged ≥65 years (“65y+”); (3) in adults aged ≥75 years (“75y+”) to “no intervention” and to each other. Both costs and quality-adjusted life-years (QALYs) were discounted at country-specific discount rates and the analysis was conducted from both the healthcare payers’ and societal perspectives. Value of information, probabilistic sensitivity and scenario analyses identified influential drivers. Results: Besides vaccine price, the hospitalisation estimates were most influential: (A) Using adjusted RSV-ICD-coded hospitalisations at a vaccine price of €150 per dose, no intervention was cost-effective up to willingness-to-pay (WTP) values of €150,000 per QALY gained in Denmark and the Netherlands, and up to €124,000 per QALY gained in Finland. (B) Using the adjusted RSV-confirmed dataset, the findings were consistent in Denmark and comparable in Finland. In Spain-Valencia, the 75y+ strategy became cost-effective at WTP >€55,000. (C) Using TSM-based estimates, the 75y+ strategy was cost-effective at WTP >€45,000, >€101,000, >€41,000 and >€114,000 in Denmark, Finland, the Netherlands and Spain-Valencia, respectively. Sensitivity analyses showed that the (in-hospital) case fatality ratio and the specification of its age dependency were both influential. Duration of protection was found more influential than a variety of plausible waning patterns over the duration of protection. Conclusions: Data gaps and uncertainties on the RSV-related burden in older adults persist and influence the cost-effectiveness of RSV vaccination. More refined age- and country-specific data on the RSV attributable burden are crucial to aid decision making.
Complement-mediated enhancement of SARS-CoV-2 antibody neutralisation potency in vaccinated individuals.
With the continued emergence of SARS-CoV-2 variants and concerns of waning immunity, there is a need for better defined correlates of protection to aid future vaccine and therapeutic developments. Whilst neutralising antibody titres are associated with protection, these are typically determined in the absence of the complement system, which has the potential to enhance neutralisation titres and strengthen correlates with protection in vivo. Here we show that replenishment of the complement system in neutralisation assays can significantly enhance neutralisation titres, with up to an ~83-fold increase in neutralisation of the BA.1.1.529 strain using cross-reactive sera from vaccination against the ancestral strain. The magnitude of enhancement significantly varies between individuals, viral strains (wild-type/VIC01 and Omicron/BA.1), and cell lines (Vero E6 and Calu-3), and is abrogated following heat-inactivation of the complement source. Utilising ACE2 competition assays, we show that the mechanism of action is partially mediated by reducing ACE2-spike interactions. Through the addition of compstatin (a C3 inhibitor) to live virus neutralisation assays, the complement protein C3 is shown to be required for maximum efficiency. These findings further our understanding of SARS-CoV-2 immunity and neutralisation, with implications for protection against emerging variants and assessing future vaccine and therapeutic developments.
The respiratory syncytial virus vaccine and monoclonal antibody landscape: the road to global access.
Respiratory syncytial virus (RSV) is the second most common pathogen causing infant mortality. Additionally, RSV is a major cause of morbidity and mortality in older adults (age ≥60 years) similar to influenza. A protein-based maternal vaccine and monoclonal antibody (mAb) are now market-approved to protect infants, while an mRNA and two protein-based vaccines are approved for older adults. First-year experience protecting infants with nirsevimab in high-income countries shows a major public health benefit. It is expected that the RSV vaccine landscape will continue to develop in the coming years to protect all people globally. The vaccine and mAb landscape remain active with 30 candidates in clinical development using four approaches: protein-based, live-attenuated and chimeric vector, mRNA, and mAbs. Candidates in late-phase trials aim to protect young infants using mAbs, older infants and toddlers with live-attenuated vaccines, and children and adults using protein-based and mRNA vaccines. This Review provides an overview of RSV vaccines highlighting different target populations, antigens, and trial results. As RSV vaccines have not yet reached low-income and middle-income countries, we outline urgent next steps to minimise the vaccine delay.
Epidemiology of Group B Streptococcus: Maternal Colonization and Infant Disease in Kampala, Uganda
Abstract Background Child survival rates have improved globally, but neonatal mortality due to infections, such as group B Streptococcus (GBS), remains a significant concern. The global burden of GBS-related morbidity and mortality is substantial. However, data from low and middle-income countries is lacking. Vaccination during pregnancy could be a feasible strategy to address GBS-related disease burden. Methods We assessed maternal rectovaginal GBS colonization and neonatal disease rates in a prospective cohort of 6062 women-infant pairs. Surveillance for invasive infant disease occurred in parallel at two Kampala hospital sites. In a nested case-control study, we identified infants <90 days of age with invasive GBS disease (iGBS) (n=24) and healthy infants born to mothers colonized with GBS (n=72). We measured serotype-specific anti-capsular immunoglobulin G in cord blood/infant sera using a validated multiplex Luminex assay. Results We found a high incidence of iGBS (1.0 per 1,000 live births) within the first 90 days of life across the surveillance sites, associated with a high case fatality rate (18.2%). Maternal GBS colonization prevalence was consistent with other studies in the region (14.7%; 95% confidence interval 13.7-15.6%). IgG geometric mean concentrations were lower in cases than controls for serotypes Ia (0.005 vs 0.12 µg/mL; p=0.05), III (0.011 vs 0.036 µg/mL; p=0.07) and in an aggregate analysis of all serotypes, (0.014 vs 0.05 µg/mL; p=0.02). Conclusions We found that GBS is an important cause of neonatal and young infant disease in Uganda and confirmed that maternally derived antibodies were lower in early-onset GBS cases than in healthy exposed controls.
A 5-transcript signature for discriminating viral and bacterial etiology in pediatric pneumonia.
Pneumonia stands as the primary cause of death among children under five, yet current diagnosis methods often result in inadequate or unnecessary treatments. Our research seeks to address this gap by identifying host transcriptomic biomarkers in the blood of children with definitive viral and bacterial pneumonia. We performed RNA sequencing on 192 prospectively collected whole blood samples, including 38 controls and 154 pneumonia cases, uncovering a 5-transcript signature (genes FAM20A, BAG3, TDRD9, MXRA7, and KLF14) that effectively distinguishes bacterial from viral pneumonia (area under the curve (AUC): 0.95 [0.88-1.00]). Initial validation using combined definitive and probable cases yielded an AUC of 0.87 [0.77-0.97], while full validation in a new prospective cohort of 32 patients achieved an AUC of 0.92 [0.83-1.00]. This robust signature holds significant potential to enhance diagnostics accuracy for pediatric pneumonia, reducing diagnostic delays and unnecessary treatments and potentially transforming clinical practice.
A diagnostic host-specific transcriptome response for Mycoplasma pneumoniae pneumonia to guide pediatric patient treatment.
Mycoplasma pneumoniae causes atypical pneumonia in children and young adults. Its lack of a cell wall makes it resistant to beta-lactams, which are the first-line treatment for typical pneumonia. Current diagnostic tests are time-consuming and have low specificity, leading clinicians to administer empirical antibiotics. Using a LASSO regression simulation approach and blood microarray data from 107 children with pneumonia (including 30 M. pneumoniae) we identify eight different transcriptomic signatures, ranging from 3-10 transcripts, that differentiate mycoplasma pneumonia from other bacterial/viral pneumonias with high accuracy (AUC: 0.84-0.95). Additionally, we demonstrate that existing signatures for broadly distinguishing viral/bacterial infections and viral/bacterial pneumonias are ineffective in distinguishing M. pneumoniae from viral pneumonia. The new signatures are successfully validated in an independent RNAseq cohort of children with pneumonia, demonstrating their robustness. The high sensibility of these signatures presents a valuable opportunity to guide the treatment and management of M. pneumoniae pneumonia patients.
Acceptability of the gonorrhoea human challenge model to accelerate vaccine development in UK men.
BACKGROUND: 281 million people worldwide were diagnosed with a bacterial sexually transmitted infection (STI) in 2020. Antimicrobial therapy for bacterial STIs is a key contributor to antimicrobial resistance (AMR) and multidrug resistant gonorrhoea is an urgent global health threat. Development of an efficacious gonorrhoea vaccine is a global health priority to address AMR. The controlled human infection model for gonorrhoea (GC-CHIM) could accelerate gonorrhoea vaccine development. This work sought to assess the acceptability of the urogenital model to UK men. METHODS: A mixed-methods study of UK men aged 18-35 years old was undertaken to assess acceptability of the urogenital GC-CHIM to UK men and attitudes to STI research, vaccines and AMR. Participants completed an online survey indicating their agreement with a series of statements using a Likert scale. Semi-structured interviews were performed on a subset of participants to gain insight into their survey responses. RESULTS: Survey responses from 72 participants and 13 interviewees highlighted stigma associated with STIs as a key barrier to, and perceived risk of, participation in STI research and GC-CHIM studies. Financial reimbursement was an important motivator, and some felt this should include compensation for intimate procedures, potential embarrassment and sexual abstinence. Individuals willing to participate in a GC-CHIM study were more likely to have personal experience of STIs, be educated to postgraduate level and describe their sexuality as gay or bisexual than those who were ambivalent or opposed to participation. CONCLUSIONS: Recruitment of participants to UK urogenital GC-CHIM studies is feasible. Sexual abstinence can be a significant inconvenience for individuals that could be recognised via reimbursement. Care should be taken generalising results from STI vaccine research where participants may not be representative of the general population. Investigators in STI research should recognise stigmatisation as a potential risk for participants and promote their STI research sensitively as a means to counter misinformation and stigma.
Absolute quantification of rare gene targets in limited samples using crude lysate and ddPCR
Accurate quantification of rare genes from limited clinical samples is crucial for research purposes but is technically challenging, especially due to nucleic acid extraction. Using the commercially available genomic DNA (gDNA) extraction kits, which mostly include a DNA purification step through silica columns, magnetic beads or ethanol precipitation, are the preferred choice for many researchers. These kits, however, have a minimum cell number requirement for optimal DNA quality and yield. They are not ideal for use for clinical samples with limited cell numbers. Here, we report the development and validation of a novel crude lysate method for preparing DNA for the absolute quantification of rare genes, TRECs in our case, by droplet digital PCR (ddPCR), from infrequent cells, that removes the need for DNA extraction. Multiple optimization steps and analytical validation of this novel assay was performed on PBMCs extracted from the blood of healthy donors. The newly developed assay shows good agreement with standard ddPCR and has high accuracy, specificity, and reproducibility; additionally, it can also be applied to fixed and permeabilized cells. The assay has the potential to be used for quantification of other trace targets from limited cell samples.
Development and validation of the Oxford Benchmark Scale for Rating Vaccine Technologies (OBSRVT), a scale for assessing public attitudes to next-generation vaccine delivery technologies.
Next-generation vaccine delivery technologies may provide significant gains from both a technical and behavioral standpoint, but no scale has yet been developed to assess public attitudes to novel vaccine delivery technologies. We therefore performed a cross-sectional validation study that included 1,001 demographically representative participants from the UK and US to develop and validate a novel scale, the Oxford Benchmark Scale for Rating Vaccine Technologies (OBSRVT). A sample of 500 UK participants was used to perform exploratory factor analysis with categorical variables (using a polychoric correlation matrix) followed by promax oblique factor rotation to develop the initial model. This yielded a 15-item 4-domain scale with domains including acceptance (6 items), effectiveness (4 items), comfort (3 items), and convenience (2 items). This model was tested for robustness on a 501-participant demographically representative sample from the US. A confirmatory factor analysis with a Satorra-Bentler scaled test statistic was performed, which demonstrated adequate goodness of fit statistics including the root mean squared error of approximation (0.057), standardized root mean squared residual (0.053), and comparative fit index (0.938). Reliability as internal consistency was excellent (alpha = 0.92). Convergent validity with the Oxford Needle Experience Scale was supported by an adequate correlation (r = 0.31, p
Etiology and Antimicrobial Resistance of Culture-Positive Infections in Ugandan Infants: A Cohort Study of 7000 Neonates and Infants.
BACKGROUND: Epidemiological evidence about the etiology and antimicrobial resistance of neonatal infections remains limited in low-resource settings. We aimed to describe the etiology of neonatal infections in a prospective observational cohort study conducted at two hospital sites in Kampala, Uganda. METHODS: Babies admitted to either unit with risk factors or signs of sepsis, pneumonia, or meningitis had a blood culture, nasopharyngeal swab, and lumbar puncture (if indicated) collected. Basic demographics were collected, and babies were followed up until discharge or death to determine admission outcome. Blood cultures were processed using the BACTEC system and identification confirmed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Cerebrospinal fluid was processed using standard microbiological testing and swabs were processed using the multiplex real-time polymerase chain reaction assay. Antimicrobial susceptibilities of bacterial isolates to World Health Organization-recommended first-line antibiotics (ampicillin or benzylpenicillin and gentamicin) were assessed using e-tests. RESULTS: A total of 7323 infants with signs or risk factors for sepsis had blood cultures, 2563 had nasopharyngeal swabs, and 23 had lumbar punctures collected. Eleven percent of blood cultures and 8.6% of swabs were positive. Inpatient mortality was 12.1%, with 27.7% case fatality observed among infants with Gram-negative bloodstream infections. Escherichia coli (14.8%), Acinetobacter spp. (10.3%), and Klebsiella spp. (7.6%), were notable contributors to Gram-negative sepsis, whereas Group B Streptococcus was the predominant Gram-positive pathogen identified (13.5%). Almost 60% of Gram-negative pathogens were ampicillin- and gentamicin-resistant. CONCLUSIONS: Our study demonstrates high levels of antimicrobial resistance and inpatient mortality from neonatal sepsis in the first months of life in Uganda. This underscores the pressing need for revised, context-specific antimicrobial treatment guidelines that account for the evolving landscape of antimicrobial resistance in neonatal sepsis.
“Bye-Bye Germs”: Respiratory Tract Infection Prevention—An Education Intervention for Children
Becoming one of the first studies in the field to do so, specially developed educational interventions (Germ’s Journey), designed to teach children about respiratory tract infection prevention, were delivered to 273 pupils aged five to six across five primary schools in the U.K. The intervention aimed to increase understanding of pathogens and respiratory tract illness, transmission and infection prevention, and preparedness for future pandemics due to a lack of such resources for young children at present. To assess the impact of the intervention, children were asked five questions related to knowledge of pathogens, transmission of infection, and infection prevention directly before and after activity-based workshops, as well as one month later. Responses were scored for pupils’ level of knowledge; differences in the frequency of responses between the time points were analysed using Pearson’s chi-squared test. Teachers also took part in semi-structured interviews to evaluate the workshop from the educators’ points of view. Children showed increased knowledge in all three areas immediately after the workshops. This improvement was retained to a lesser or equal extent one month following the learning intervention workshop. The consistent use of teaching resources and interventions such as Germ’s Journey should be implemented in the school curriculum in order to increase understanding and reduce the transmission of respiratory tract illness. Specially designed activity-based workshops using a range of learning skills can help young children to understand the link between pathogens, and infection transmission and control.
IL7 genetic variation and toxicity to immune checkpoint blockade in patients with melanoma.
Treatment with immune checkpoint blockade (ICB) frequently triggers immune-related adverse events (irAEs), causing considerable morbidity. In 214 patients receiving ICB for melanoma, we observed increased severe irAE risk in minor allele carriers of rs16906115, intronic to IL7. We found that rs16906115 forms a B cell-specific expression quantitative trait locus (eQTL) to IL7 in patients. Patients carrying the risk allele demonstrate increased pre-treatment B cell IL7 expression, which independently associates with irAE risk, divergent immunoglobulin expression and more B cell receptor mutations. Consistent with the role of IL-7 in T cell development, risk allele carriers have distinct ICB-induced CD8+ T cell subset responses, skewing of T cell clonality and greater proportional repertoire occupancy by large clones. Finally, analysis of TCGA data suggests that risk allele carriers independently have improved melanoma survival. These observations highlight key roles for B cells and IL-7 in both ICB response and toxicity and clinical outcomes in melanoma.
Relation Between the Dantu Blood Group Variant and Bacteremia in Kenyan Children: A Population-Based Case-Control Study.
BACKGROUND: The Dantu blood group variant protects against Plasmodium falciparum infections, but its wider consequences have not been previously explored. Here, we investigate the impact of Dantu on susceptibility to bacteremia. METHODS: We conducted a case-control study in children presenting with community-acquired bacteremia to Kilifi County Hospital in Kenya between 1998 and 2010. We used logistic regression to test for associations between the Dantu marker single-nucleotide polymorphism rs186873296 A > G and both all-cause and pathogen-specific bacteremia under an additive model. We used date of admission as a proxy measure of malaria transmission intensity, given known differences in malaria prevalence over the course of the study. RESULTS: Dantu was associated with protection from all-cause bacteremia (OR, 0.81; P = .014), the association being greatest in homozygotes (OR, 0.30; P = .013). This protection was shared across the major bacterial pathogens but, notably, was only significant during the era of high malaria transmission pre-2003 (OR, 0.79; P = .023). CONCLUSIONS: Consistent with previous studies showing the indirect impact on bacteremia risk of other malaria-associated red cell variants, our study also shows that Dantu is protective against bacteremia via its effect on malaria risk. Dantu does not appear to be under balancing selection through an increased risk of bacterial infections.