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Pollard AJ, Garner S, Patel S, Jerreat M. A Retrospective Service- Evaluation of Implant Success, Survival, Periimplant Health and Prosthetic Complications in a Cohort of Head and Neck Cancer Patients. THE EUROPEAN JOURNAL OF PROSTHODONTICS AND RESTORATIVE DENTISTRY 2023; 31:92-103. [PMID: 35917210 DOI: 10.1922/ejprd_2441pollard12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
OBJECTIVES To determine the success, survival, peri-implant health and prosthetic complications in head and neck cancer patients receiving oral rehabilitation utilising dental implants between 2008 and the present day. MATERIALS AND METHODS Service evaluation. Survival Group: Retrospective review of records to determine implant survival and prosthetic complications. Success Group: Examination to determine implant success and health. RESULTS Survival Group: 260 implants in 81 individuals, median follow up 49.2 months. 89.3% implant survival at 96 months, no further failures up to 133 months. 40.9% individuals required repair or remake of prosthesis by 72 months - mostly denture re-lines. Success group: 164 implants in 48 individuals, median follow up 56 months. Peri-implant mucositis detected in 22% of fixtures (37.5% individuals); peri-implantitis in 12.8% (25% individuals); 33.3% fixtures exhibiting periimplantitis at 120 months. Previous smoking significantly associated with development of peri-implantitis (HR 2.372, p=0.032, 95CI:1.232, 93.317). Compromised survival (e.g. peri-implantitis), absolute (not in mouth) or clinical failure estimated to occur in 28.1% fixtures at 101 months, mostly due to peri-implantitis. CONCLUSIONS There is a large burden of ongoing care in this cohort, requiring interventions to improve peri-implant health and maintain complex prostheses. Oral rehabilitation and ongoing maintenance in this cohort is complex and multi-disciplinary.
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McCann N, Emary K, Singh N, Mclean F, Camara S, Jones E, Kim YC, Liu X, Greenland M, Conlin K, Hill J, Verheul M, Robinson H, Angus B, Ramasamy MN, Levine MM, Pollard AJ. Accelerating clinical development of a live attenuated vaccine against Salmonella Paratyphi A (VASP): study protocol for an observer-participant-blind randomised control trial of a novel oral vaccine using a human challenge model of Salmonella Paratyphi A infection in healthy adult volunteers. BMJ Open 2023; 13:e068966. [PMID: 37225278 DOI: 10.1136/bmjopen-2022-068966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 05/26/2023] Open
Abstract
INTRODUCTION This is the first efficacy study of an oral live attenuated vaccine against Salmonella Paratyphi A using a human challenge model of paratyphoid infection. S. Paratyphi A is responsible for 3.3 million cases of enteric fever every year, with over 19 000 deaths. Although improvements to sanitation and access to clean water are vital to reduce the burden of this condition, vaccination offers a cost-effective, medium-term solution. Efficacy trials of potential S. Paratyphi vaccine candidates in the field are unlikely to be feasible given the large number of participants required. Human challenge models therefore offer a unique, cost-effective solution to test efficacy of such vaccines. METHODS AND ANALYSIS This is an observer-blind, randomised, placebo-controlled trial phase I/II of the oral live-attenuated vaccine against S. Paratyphi A, CVD 1902. Volunteers will be randomised 1:1 to receive two doses of CVD 1902 or placebo, 14 days apart. One month following second vaccination all volunteers will ingest S. Paratyphi A bacteria with a bicarbonate buffer solution. They will be reviewed daily in the following 14 days and diagnosed with paratyphoid infection if the predefined microbiological or clinical diagnostic criteria are met. All participants will be treated with antibiotics on diagnosis, or at day 14 postchallenge if not diagnosed. The vaccine efficacy will be determined by comparing the relative attack rate, that is, the proportion of those diagnosed with paratyphoid infection, in the vaccine and placebo groups. ETHICS AND DISSEMINATION Ethical approval for this study has been obtained from the Berkshire Medical Research Ethics Committee (REC ref 21/SC/0330). The results will be disseminated via publication in a peer-reviewed journal and presentation at international conferences. TRIAL REGISTRATION NUMBER ISRCTN15485902.
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Dold C, Zhu H, Silva-Reyes L, Blackwell L, Linder A, Bewley K, Godwin K, Fotheringham S, Charlton S, Kim YC, Pollard AJ, Rollier CS. Immunisation with purified Coxiella burnetii phase I lipopolysaccharide confers partial protection in mice independently of co-administered adenovirus vectored vaccines. Vaccine 2023; 41:3047-3057. [PMID: 37037709 PMCID: PMC10914673 DOI: 10.1016/j.vaccine.2023.04.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 03/25/2023] [Accepted: 04/04/2023] [Indexed: 04/12/2023]
Abstract
Q fever is a highly infectious zoonosis caused by the Gram-negative bacterium Coxiella burnetii. The worldwide distribution of Q fever suggests a need for vaccines that are more efficacious, affordable, and does not induce severe adverse reactions in vaccine recipients with pre-existing immunity against Q fever. Potential Q fever vaccine antigens include lipopolysaccharide (LPS) and several C. burnetii surface proteins. Antibodies elicited by purified C. burnetii lipopolysaccharide (LPS) correlate with protection against Q fever, while antigens encoded by adenoviral vectored vaccines can induce cellular immune responses which aid clearing of intracellular pathogens. In the present study, the immunogenicity and the protection induced by adenoviral vectored constructs formulated with the addition of LPS were assessed. Multiple vaccine constructs encoding single or fusion antigens from C. burnetii were synthesised. The adenoviral vectored vaccine constructs alone elicited strong cellular immunity, but this response was not correlative with protection in mice. However, vaccination with LPS was significantly associated with lower weight loss post-bacterial challenge independent of co-administration with adenoviral vaccine constructs, supporting further vaccine development based on LPS.
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Koen AL, Izu A, Baillie V, Kwatra G, Cutland CL, Fairlie L, Padayachee SD, Dheda K, Barnabas SL, Bhorat QE, Briner C, Ahmed K, Bhikha S, Bhiman JN, du Plessis J, Esmail A, Horne E, Hwa SH, Oommen-Jose A, Lambe T, Laubscher M, Malahleha M, Benade G, McKenzie S, Oelofse S, Patel F, Pillay S, Rhead S, Rodel H, Taoushanis C, Tegally H, Thombrayil A, Villafana TL, Gilbert S, Pollard AJ, Madhi SA. Efficacy of primary series AZD1222 (ChAdOx1 nCoV-19) vaccination against SARS-CoV-2 variants of concern: Final analysis of a randomized, placebo-controlled, phase 1b/2 study in South African adults (COV005). Vaccine 2023; 41:3486-3492. [PMID: 37149443 PMCID: PMC10133888 DOI: 10.1016/j.vaccine.2023.04.058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 04/21/2023] [Accepted: 04/21/2023] [Indexed: 05/08/2023]
Abstract
COVID-19 vaccine efficacy (VE) has been observed to vary against antigenically distinct SARS-CoV-2 variants of concern (VoC). Here we report the final analysis of VE and safety from COV005: a phase 1b/2, multicenter, double-blind, randomized, placebo-controlled study of primary series AZD1222 (ChAdOx1 nCoV-19) vaccination in South African adults aged 18-65 years. South Africa's first, second, and third waves of SARS-CoV-2 infections were respectively driven by the ancestral SARS-CoV-2 virus (wild type, WT), and SARS-CoV-2 Beta and Delta VoCs. VE against asymptomatic and symptomatic infection was 90.6% for WT, 6.7% for Beta and 77.1% for Delta. No cases of severe COVID-19 were documented ahead of unblinding. Safety was consistent with the interim analysis, with no new safety concerns identified. Notably, South Africa's Delta wave occurred ≥ 9 months after primary series vaccination, suggesting that primary series AZD1222 vaccination offers a good durability of protection, potentially due to an anamnestic response. Clinical trial identifier: CT.gov NCT04444674.
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Yin Z, Chen JL, Lu Y, Wang B, Godfrey L, Mentzer AJ, Yao X, Liu G, Wellington D, Zhao Y, Wing PAC, Dejnirattisa W, Supasa P, Liu C, Hublitz P, Beveridge R, Waugh C, Clark SA, Clark K, Sopp P, Rostron T, Mongkolsapaya J, Screaton GR, Ogg G, Ewer K, Pollard AJ, Gilbert S, Knight JC, Lambe T, Smith GL, Dong T, Peng Y. Evaluation of T cell responses to naturally processed variant SARS-CoV-2 spike antigens in individuals following infection or vaccination. Cell Rep 2023; 42:112470. [PMID: 37141092 PMCID: PMC10121105 DOI: 10.1016/j.celrep.2023.112470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 03/20/2023] [Accepted: 04/18/2023] [Indexed: 05/05/2023] Open
Abstract
Most existing studies characterizing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific T cell responses are peptide based. This does not allow evaluation of whether tested peptides are processed and presented canonically. In this study, we use recombinant vaccinia virus (rVACV)-mediated expression of SARS-CoV-2 spike protein and SARS-CoV-2 infection of angiotensin-converting enzyme (ACE)-2-transduced B cell lines to evaluate overall T cell responses in a small cohort of recovered COVID-19 patients and uninfected donors vaccinated with ChAdOx1 nCoV-19. We show that rVACV expression of SARS-CoV-2 antigen can be used as an alternative to SARS-CoV-2 infection to evaluate T cell responses to naturally processed spike antigens. In addition, the rVACV system can be used to evaluate the cross-reactivity of memory T cells to variants of concern (VOCs) and to identify epitope escape mutants. Finally, our data show that both natural infection and vaccination could induce multi-functional T cell responses with overall T cell responses remaining despite the identification of escape mutations.
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Bijukchhe SM, O'Reilly PJ, Theiss-Nyland K, Gurung M, Pokhrel B, Kelly S, Acharya S, Maharjan S, Shrestha A, Pandey B, Lama M, Shrestha I, Voysey M, Eordogh A, Shrestha S, Feng ES, Li G, Shah G, Pollard AJ, Shrestha S. COVID-19 vaccine effectiveness and variants in Nepal: study protocol for a test-negative case-control study with SARS-CoV-2 genetic sequencing. BMJ Open 2023; 13:e068334. [PMID: 37072367 PMCID: PMC10123857 DOI: 10.1136/bmjopen-2022-068334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 04/20/2023] Open
Abstract
INTRODUCTION Inactivated, viral vector and mRNA vaccines have been used in the Nepali COVID-19 vaccination programme but there is little evidence on the effectiveness of these vaccines in this setting. The aim of this study is to describe COVID-19 vaccine effectiveness in Nepal and provide information on infections with SARS-CoV-2 variants. METHODS AND ANALYSIS This is a hospital-based, prospective test-negative case-control study conducted at Patan Hospital, Kathmandu. All patients >18 years of age presenting to Patan Hospital with COVID-19-like symptoms who have received a COVID-19 antigen/PCR test are eligible for inclusion. The primary outcome is vaccine effectiveness of licensed COVID-19 vaccines against laboratory-confirmed COVID-19 disease.After enrolment, information will be collected on vaccine status, date of vaccination, type of vaccine, demographics and other medical comorbidities. The primary outcome of interest is laboratory-confirmed SARS-CoV-2 infection. Cases (positive for SARS-CoV-2) and controls (negative for SARS-CoV-2) will be enrolled in a 1:4 ratio. Vaccine effectiveness against COVID-19 disease will be analysed by comparing vaccination status with SARS-CoV-2 test results.Positive SARS-CoV-2 samples will be sequenced to identify circulating variants and estimate vaccine effectiveness against common variants.Measuring vaccine effectiveness and identifying SARS-CoV-2 variants in Nepal will help to inform public health efforts. Describing disease severity in relation to specific SARS-CoV-2 variants and vaccine status will also inform future prevention and care efforts. ETHICS AND DISSEMINATION Ethical approval was obtained from the University of Oxford Tropical Ethics Committee (OxTREC) (ref: 561-21) and the Patan Academy of Health Sciences Institutional Review Board (ref: drs2111121578). The protocol and supporting study documents were approved for use by the Nepal Health Research Council (NHRC 550-2021). Results will be disseminated in peer-reviewed journals and to the public health authorities in Nepal.
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Khanam F, Babu G, Rahman N, Liu X, Rajib NH, Ahmed SU, Hossen MI, Biswas PK, Kelly S, Thesis-Nyland K, Mujadidi Y, McMillan NAJ, Pollard AJ, Clemens JD, Qadri F. Immune responses in children after vaccination with a typhoid Vi-tetanus toxoid conjugate vaccine in Bangladesh. Vaccine 2023; 41:3137-3140. [PMID: 37061369 DOI: 10.1016/j.vaccine.2023.04.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 04/15/2022] [Accepted: 04/04/2023] [Indexed: 04/17/2023]
Abstract
A cluster-randomized trial of Vi-TT was conducted in Dhaka, Bangladesh, using JE vaccine as the control. A subset of 1,500 children were randomly selected on 2:1 basis (Vi-TT vs JE) to assess immune response. Blood was collected before vaccination, and on days 28, 545 and 730 post-vaccination and plasma anti-Vi-IgG response was measured. A robust, persistent antibody response was induced after single dose of Vi-TT, even after 2 years of vaccination. While there is no accepted serological antibody threshold of protection, analyzing the antibodies of children who received Vi-TT provides evidence that may later be useful in predicting population protection.
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Khanam F, Kim DR, Liu X, Voysey M, Pitzer VE, Zaman K, Pollard AJ, Qadri F, Clemens JD. Assessment of vaccine herd protection in a cluster-randomised trial of Vi conjugate vaccine against typhoid fever: results of further analysis. EClinicalMedicine 2023; 58:101925. [PMID: 37090439 PMCID: PMC10114505 DOI: 10.1016/j.eclinm.2023.101925] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 03/07/2023] [Accepted: 03/09/2023] [Indexed: 04/25/2023] Open
Abstract
Background A cluster-randomised trial of Vi-tetanus toxoid (Vi-TT) conjugate vaccine conducted in urban Bangladeshi children found a high level of direct protection by Vi-TT but no significant vaccine herd protection. We reassessed the trial using a "fried egg" analysis to evaluate whether herd protection might have been obscured by transmission of typhoid into the clusters from the outside. Methods A participant- and observer-blind, cluster-randomised trial was conducted between February 14, 2018 and August 12, 2019 in three wards of Mirpur, a densely populated urban area of Dhaka, Bangladesh. Children 9 months to under 16 years of age in 150 geographic clusters, which had a total of 311,289 persons present at baseline or entering during follow-up, were randomised by cluster to a single-dose of Vi-TT or Japanese encephalitis (JE) vaccine. Vi-TT protection against typhoid fever, detected at 8 treatment centres serving the study population, was compared in the original clusters for the trial, and for progressively more central subclusters ("yolks" of the "fried egg") of the cluster residents. If transmission of typhoid into the clusters had diluted observed vaccine herd protection, we hypothesised that analysis of the innermost "yolks" would reveal vaccine herd protection that was not evident in analysis of the entire clusters. The trial is registered at www.isrctn.com as ISRCTN11643110. Findings At ≤18 months of follow-up, total vaccine effectiveness (protection of Vi-TT recipients relative to JE vaccine recipients) was 85% (95% CI: 76%, 90%); indirect effectiveness (protection of non-Vi-TT recipients in Vi-TT clusters relative to non-JE vaccine recipients in JE vaccine clusters) was 17% (95% CI: -13%, 40%); and overall effectiveness (protection of all residents in the Vi-TT clusters relative to all residents of the JE vaccine clusters) was 57% (95% CI: 44%, 66%). Analyses of subpopulations in inner 75%, 50% and 25% "yolks" of the clusters failed to reveal significant changes in any of these estimates. Interpretation Our analysis did not reveal Vi-TT herd protection in the trial. Consideration should be given to exploring whether targeting adults as well as children with Vi-TT yields appreciable levels of vaccine herd protection. Funding Bill & Melinda Gates Foundation (OPP1151153, INV-025388).
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Voysey M, Flaxman A, Aboagye J, Aley PK, Belij-Rammerstorfer S, Bibi S, Bittaye M, Cappuccini F, Charlton S, Clutterbuck EA, Davies S, Dold C, Edwards NJ, Ewer KJ, Faust SN, Folegatti PM, Fowler J, Gilbride C, Gilbert SC, Godfrey L, Hallis B, Humphries HE, Jenkin D, Kerridge S, Mujadidi YF, Plested E, Ramasamy MN, Robinson H, Sanders H, Snape MD, Song R, Thomas KM, Ulaszewska M, Woods D, Wright D, Pollard AJ, Lambe T. Persistence of the immune response after two doses of ChAdOx1 nCov-19 (AZD1222): 1 year of follow-up of two randomized controlled trials. Clin Exp Immunol 2023; 211:280-287. [PMID: 36729167 PMCID: PMC10038323 DOI: 10.1093/cei/uxad013] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 01/04/2023] [Accepted: 01/27/2023] [Indexed: 02/03/2023] Open
Abstract
The trajectory of immune responses following the primary dose series determines the decline in vaccine effectiveness over time. Here we report on maintenance of immune responses during the year following a two-dose schedule of ChAdOx1 nCoV-19/AZD1222, in the absence of infection, and also explore the decay of antibody after infection. Total spike-specific IgG antibody titres were lower with two low doses of ChAdOx1 nCoV-19 vaccines (two low doses) (P = 0.0006) than with 2 standard doses (the approved dose) or low dose followed by standard dose vaccines regimens. Longer intervals between first and second doses resulted in higher antibody titres (P < 0.0001); however, there was no evidence that the trajectory of antibody decay differed by interval or by vaccine dose, and the decay of IgG antibody titres followed a similar trajectory after a third dose of ChAdOx1 nCoV-19. Trends in post-infection samples were similar with an initial rapid decay in responses but good persistence of measurable responses thereafter. Extrapolation of antibody data, following two doses of ChAdOx1 nCov-19, demonstrates a slow rate of antibody decay with modelling, suggesting that antibody titres are well maintained for at least 2 years. These data suggest a persistent immune response after two doses of ChAdOx1 nCov-19 which will likely have a positive impact against serious disease and hospitalization.
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Mao Z, Li X, Dacosta-Urbieta A, Billard MN, Wildenbeest J, Korsten K, Martinón-Torres F, Heikkinen T, Cunningham S, Snape MD, Robinson H, Pollard AJ, Postma M, Dervaux B, Hens N, Bont L, Bilcke J, Beutels P. Economic burden and health-related quality-of-life among infants with respiratory syncytial virus infection: A multi-country prospective cohort study in Europe. Vaccine 2023; 41:2707-2715. [PMID: 36941154 DOI: 10.1016/j.vaccine.2023.03.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 02/06/2023] [Accepted: 03/10/2023] [Indexed: 03/23/2023]
Abstract
BACKGROUND Respiratory syncytial virus (RSV) causes a considerable disease burden in young children globally, but reliable estimates of RSV-related costs and health-related quality-of-life (HRQoL) are scarce. This study aimed to evaluate the RSV-associated costs and HRQoL effects in infants and their caregivers in four European countries. METHODS Healthy term-born infants were recruited at birth and actively followed up in four European countries. Symptomatic infants were systematically tested for RSV. Caregivers recorded the daily HRQoL of their child and themselves, measured by a modified EQ-5D with Visual Analogue Scale, for 14 consecutive days or until symptoms resolved. At the end of each RSV episode, caregivers reported healthcare resource use and work absenteeism. Direct medical costs per RSV episode were estimated from a healthcare payer's perspective and indirect costs were estimated from a societal perspective. Means and 95% confidence intervals (CI) of direct medical costs, total costs (direct costs + productivity loss) and quality-adjusted life-day (QALD) loss per RSV episode were estimated per RSV episode, as well as per subgroup (medical attendance, country). RESULTS Our cohort of 1041 infants experienced 265 RSV episodes with a mean symptom duration of 12.5 days. The mean (95% CI) cost per RSV episode was €399.5 (242.3, 584.2) and €494.3 (317.7, 696.1) from the healthcare payer's and societal perspective, respectively. The mean QALD loss per RSV episode of 1.9 (1.7, 2.1) was independent of medical attendance (in contrast to costs, which also differed by country). Caregiver and infant HRQoL evolved similarly. CONCLUSION This study fills essential gaps for future economic evaluations by prospectively estimating direct and indirect costs and HRQoL effects on healthy term infants and caregivers separately, for both medically attended (MA) and non-MA laboratory-confirmed RSV episodes. We generally observed greater HRQoL losses than in previous studies which used non-community and/or non-prospective designs.
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Bu T, Gao H, Yao Y, Wang J, Pollard AJ, Legge EJ, Clifford CA, Delvallée A, Ducourtieux S, Lawn MA, Babic B, Coleman VA, Jämting Å, Zou S, Chen M, Jakubek ZJ, Iacob E, Chanthawong N, Mongkolsuttirat K, Zeng G, Almeida CM, He BC, Hyde L, Ren L. Thickness measurements of graphene oxide flakes using atomic force microscopy: results of an international interlaboratory comparison. NANOTECHNOLOGY 2023; 34:225702. [PMID: 36848668 DOI: 10.1088/1361-6528/acbf58] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2022] [Accepted: 02/27/2023] [Indexed: 06/18/2023]
Abstract
Flake thickness is one of the defining properties of graphene-related 2D materials (GR2Ms), and therefore requires reliable, accurate, and reproducible measurements with well-understood uncertainties. This is needed regardless of the production method or manufacturer because it is important for all GR2M products to be globally comparable. An international interlaboratory comparison on thickness measurements of graphene oxide flakes using atomic force microscopy has been completed in technical working area 41 of versailles project on advanced materials and standards. Twelve laboratories participated in the comparison project, led by NIM, China, to improve the equivalence of thickness measurement for two-dimensional flakes. The measurement methods, uncertainty evaluation and a comparison of the results and analysis are reported in this manuscript. The data and results of this project will be directly used to support the development of an ISO standard.
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Yap PL, Farivar F, Jämting ÅK, Coleman VA, Gnaniah S, Mansfield E, Pu C, Landi SM, David MV, Flahaut E, Aizane M, Barnes M, Gallerneault M, Locatelli MD, Jacquinot S, Slough CG, Menzel J, Schmölzer S, Ren L, Pollard AJ, Losic D. International Interlaboratory Comparison of Thermogravimetric Analysis of Graphene-Related Two-Dimensional Materials. Anal Chem 2023; 95:5176-5186. [PMID: 36917706 DOI: 10.1021/acs.analchem.2c03575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023]
Abstract
Research on graphene-related two-dimensional (2D) materials (GR2Ms) in recent years is strongly moving from academia to industrial sectors with many new developed products and devices on the market. Characterization and quality control of the GR2Ms and their properties are critical for growing industrial translation, which requires the development of appropriate and reliable analytical methods. These challenges are recognized by International Organization for Standardization (ISO 229) and International Electrotechnical Commission (IEC 113) committees to facilitate the development of these methods and standards which are currently in progress. Toward these efforts, the aim of this study was to perform an international interlaboratory comparison (ILC), conducted under Versailles Project on Advanced Materials and Standards (VAMAS) Technical Working Area (TWA) 41 "Graphene and Related 2D Materials" to evaluate the performance (reproducibility and confidence) of the thermogravimetric analysis (TGA) method as a potential new method for chemical characterization of GR2Ms. Three different types of representative and industrially manufactured GR2Ms samples, namely, pristine few-layer graphene (FLG), graphene oxide (GO), and reduced graphene oxide (rGO), were used and supplied to ILC participants to complete the study. The TGA method performance was evaluated by a series of measurements of selected parameters of the chemical and physical properties of these GR2Ms including the number of mass loss steps, thermal stability, temperature of maximum mass change rate (Tp) for each decomposition step, and the mass contents (%) of moisture, oxygen groups, carbon, and impurities (organic and non-combustible residue). TGA measurements determining these parameters were performed using the provided optimized TGA protocol on the same GR2Ms by 12 participants across academia, industry stakeholders, and national metrology institutes. This paper presents these results with corresponding statistical analysis showing low standard deviation and statistical conformity across all participants that confirm that the TGA method can be satisfactorily used for characterization of these parameters and the chemical characterization and quality control of GR2Ms. The common measurement uncertainty for each parameter, key contribution factors were identified with explanations and recommendations for their elimination and improvements toward their implementation for the development of the ISO/IEC standard for chemical characterization of GR2Ms.
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Moore SC, Kronsteiner B, Longet S, Adele S, Deeks AS, Liu C, Dejnirattisai W, Reyes LS, Meardon N, Faustini S, Al-Taei S, Tipton T, Hering LM, Angyal A, Brown R, Nicols AR, Dobson SL, Supasa P, Tuekprakhon A, Cross A, Tyerman JK, Hornsby H, Grouneva I, Plowright M, Zhang P, Newman TAH, Nell JM, Abraham P, Ali M, Malone T, Neale I, Phillips E, Wilson JD, Murray SM, Zewdie M, Shields A, Horner EC, Booth LH, Stafford L, Bibi S, Wootton DG, Mentzer AJ, Conlon CP, Jeffery K, Matthews PC, Pollard AJ, Brown A, Rowland-Jones SL, Mongkolsapaya J, Payne RP, Dold C, Lambe T, Thaventhiran JED, Screaton G, Barnes E, Hopkins S, Hall V, Duncan CJA, Richter A, Carroll M, de Silva TI, Klenerman P, Dunachie S, Turtle L. Evolution of long-term vaccine-induced and hybrid immunity in healthcare workers after different COVID-19 vaccine regimens. MED 2023; 4:191-215.e9. [PMID: 36863347 PMCID: PMC9933851 DOI: 10.1016/j.medj.2023.02.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 02/09/2023] [Accepted: 02/10/2023] [Indexed: 02/18/2023]
Abstract
BACKGROUND Both infection and vaccination, alone or in combination, generate antibody and T cell responses against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, the maintenance of such responses-and hence protection from disease-requires careful characterization. In a large prospective study of UK healthcare workers (HCWs) (Protective Immunity from T Cells in Healthcare Workers [PITCH], within the larger SARS-CoV-2 Immunity and Reinfection Evaluation [SIREN] study), we previously observed that prior infection strongly affected subsequent cellular and humoral immunity induced after long and short dosing intervals of BNT162b2 (Pfizer/BioNTech) vaccination. METHODS Here, we report longer follow-up of 684 HCWs in this cohort over 6-9 months following two doses of BNT162b2 or AZD1222 (Oxford/AstraZeneca) vaccination and up to 6 months following a subsequent mRNA booster vaccination. FINDINGS We make three observations: first, the dynamics of humoral and cellular responses differ; binding and neutralizing antibodies declined, whereas T and memory B cell responses were maintained after the second vaccine dose. Second, vaccine boosting restored immunoglobulin (Ig) G levels; broadened neutralizing activity against variants of concern, including Omicron BA.1, BA.2, and BA.5; and boosted T cell responses above the 6-month level after dose 2. Third, prior infection maintained its impact driving larger and broader T cell responses compared with never-infected people, a feature maintained until 6 months after the third dose. CONCLUSIONS Broadly cross-reactive T cell responses are well maintained over time-especially in those with combined vaccine and infection-induced immunity ("hybrid" immunity)-and may contribute to continued protection against severe disease. FUNDING Department for Health and Social Care, Medical Research Council.
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Madhi SA, Kwatra G, Richardson SI, Koen AL, Baillie V, Cutland CL, Fairlie L, Padayachee SD, Dheda K, Barnabas SL, Bhorat QE, Briner C, Ahmed K, Aley PK, Bhikha S, Bhorat AE, Esmail A, Horne E, Kaldine H, Mukendi CK, Madzorera VS, Manamela NP, Masilela M, Hermanus ST, Motlou T, Mzindle N, Oelofse S, Patel F, Rhead S, Rossouw L, Taoushanis C, van Eck S, Lambe T, Gilbert SC, Pollard AJ, Moore PL, Izu A. Durability of ChAdOx1 nCoV-19 (AZD1222) vaccine and hybrid humoral immunity against variants including omicron BA.1 and BA.4 6 months after vaccination (COV005): a post-hoc analysis of a randomised, phase 1b-2a trial. THE LANCET. INFECTIOUS DISEASES 2023; 23:295-306. [PMID: 36273491 PMCID: PMC9584570 DOI: 10.1016/s1473-3099(22)00596-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 09/01/2022] [Accepted: 09/02/2022] [Indexed: 11/07/2022]
Abstract
BACKGROUND COVID-19 vaccine rollout is lagging in Africa, where there has been a high rate of SARS-CoV-2 infection. We aimed to evaluate the effect of SARS-CoV-2 infection before vaccination with the ChAdOx-nCoV19 (AZD1222) vaccine on antibody responses through to 180 days. METHODS We did an unmasked post-hoc immunogenicity analysis after the first and second doses of AZD1222 in a randomised, placebo-controlled, phase 1b-2a study done in seven locations in South Africa. AZD1222 recipients who were HIV-uninfected, were stratified into baseline seropositive or seronegative groups using the serum anti-nucleocapsid (anti-N) immunoglobulin G (IgG) electroluminescence immunoassay to establish SARS-CoV-2 infection before the first dose of AZD1222. Binding IgG to spike (anti-S) and receptor binding domain (anti-RBD) were measured before the first dose (day 0), second dose (day 28), day 42, and day 180. Neutralising antibody (NAb) against SARS-CoV-2 variants D614G, beta, delta, gamma, and A.VOI.V2, and omicron BA1 and BA.4 variants, were measured by pseudovirus assay (day 28, day 42, and day 180). This trial is registered with ClinicalTrials.gov, NCT04444674, and the Pan African Clinicals Trials Registry, PACTR202006922165132. FINDINGS Of 185 individuals who were randomly assigned to AZD1222, we included 91 individuals who were baseline seropositive and 58 who were baseline seronegative, in the final analysis. In the seropositive group, there was little change of anti-S IgG (and anti-RBD IgG) or neutralising antibody (NAb) titres at day 42 compared with at day 28. Anti-S (and anti-RBD) IgG geometric mean concentrations (GMCs) were higher throughout in the seropositive compared with the seronegative group, including at day 180 (GMCs 517·8 [95% CI 411·3-651·9] vs 82·1 [55·2-122·3] BAU/mL). Also D614G NAb geometric mean titres (GMTs) were higher in the seropositive group than the seronegative group, as was the percentage with titres of at least 185 (80% putative risk reduction threshold [PRRT] against wild-type-alpha COVID-19), including at day 180 (92·0% [74·0-99·0] vs 18·2% [2·3-51·8). Similar findings were observed for beta, A.VOI.V2, and gamma. For delta, BA.1, and BA.4, NAb GMTs and the proportion with titres above the PRRT were substantially higher in the seropositive compared with seronegative group at day 28 and day 42, but no longer differed between the groups by day 180. INTERPRETATION A single dose of AZD1222 in the general African population, where COVID-19 vaccine coverage is low and SARS-CoV-2 seropositivity is 90%, could enhance the magnitude and quality of antibody responses to SARS-CoV-2. FUNDING The Bill & Melinda Gates Foundation, the South African Medical Research Council, the UK Research and Innovation, the UK National Institute for Health Research, and the South African Medical Research Council. TRANSLATION For the Zulu translation of the abstract see Supplementary Materials section.
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Freeman D, Lambe S, Yu LM, Freeman J, Chadwick A, Vaccari C, Waite F, Rosebrock L, Petit A, Vanderslott S, Lewandowsky S, Larkin M, Innocenti S, McShane H, Pollard AJ, Loe BS. Injection fears and COVID-19 vaccine hesitancy. Psychol Med 2023; 53:1185-1195. [PMID: 34112276 PMCID: PMC8220023 DOI: 10.1017/s0033291721002609] [Citation(s) in RCA: 71] [Impact Index Per Article: 71.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 06/06/2021] [Accepted: 06/09/2021] [Indexed: 01/08/2023]
Abstract
BACKGROUND When vaccination depends on injection, it is plausible that the blood-injection-injury cluster of fears may contribute to hesitancy. Our primary aim was to estimate in the UK adult population the proportion of COVID-19 vaccine hesitancy explained by blood-injection-injury fears. METHODS In total, 15 014 UK adults, quota sampled to match the population for age, gender, ethnicity, income and region, took part (19 January-5 February 2021) in a non-probability online survey. The Oxford COVID-19 Vaccine Hesitancy Scale assessed intent to be vaccinated. Two scales (Specific Phobia Scale-blood-injection-injury phobia and Medical Fear Survey-injections and blood subscale) assessed blood-injection-injury fears. Four items from these scales were used to create a factor score specifically for injection fears. RESULTS In total, 3927 (26.2%) screened positive for blood-injection-injury phobia. Individuals screening positive (22.0%) were more likely to report COVID-19 vaccine hesitancy compared to individuals screening negative (11.5%), odds ratio = 2.18, 95% confidence interval (CI) 1.97-2.40, p < 0.001. The population attributable fraction (PAF) indicated that if blood-injection-injury phobia were absent then this may prevent 11.5% of all instances of vaccine hesitancy, AF = 0.11; 95% CI 0.09-0.14, p < 0.001. COVID-19 vaccine hesitancy was associated with higher scores on the Specific Phobia Scale, r = 0.22, p < 0.001, Medical Fear Survey, r = 0.23, p = <0.001 and injection fears, r = 0.25, p < 0.001. Injection fears were higher in youth and in Black and Asian ethnic groups, and explained a small degree of why vaccine hesitancy is higher in these groups. CONCLUSIONS Across the adult population, blood-injection-injury fears may explain approximately 10% of cases of COVID-19 vaccine hesitancy. Addressing such fears will likely improve the effectiveness of vaccination programmes.
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Li K, Dodds M, Spreng RL, Abraha M, Huntwork RHC, Dahora LC, Nyanhete T, Dutta S, Wille-Reece U, Jongert E, Ewer KJ, Hill AVS, Jin C, Hill J, Pollard AJ, Munir Alam S, Tomaras GD, Dennison SM. A tool for evaluating heterogeneity in avidity of polyclonal antibodies. Front Immunol 2023; 14:1049673. [PMID: 36875126 PMCID: PMC9978818 DOI: 10.3389/fimmu.2023.1049673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 01/18/2023] [Indexed: 02/18/2023] Open
Abstract
Diversity in specificity of polyclonal antibody (pAb) responses is extensively investigated in vaccine efficacy or immunological evaluations, but the heterogeneity in antibody avidity is rarely probed as convenient tools are lacking. Here we have developed a polyclonal antibodies avidity resolution tool (PAART) for use with label-free techniques, such as surface plasmon resonance and biolayer interferometry, that can monitor pAb-antigen interactions in real time to measure dissociation rate constant (kd ) for defining avidity. PAART utilizes a sum of exponentials model to fit the dissociation time-courses of pAb-antigens interactions and resolve multiple kd contributing to the overall dissociation. Each kd value of pAb dissociation resolved by PAART corresponds to a group of antibodies with similar avidity. PAART is designed to identify the minimum number of exponentials required to explain the dissociation course and guards against overfitting of data by parsimony selection of best model using Akaike information criterion. Validation of PAART was performed using binary mixtures of monoclonal antibodies of same specificity but differing in kd of the interaction with their epitope. We applied PAART to examine the heterogeneity in avidities of pAb from malaria and typhoid vaccinees, and individuals living with HIV-1 that naturally control the viral load. In many cases, two to three kd were dissected indicating the heterogeneity of pAb avidities. We showcase examples of affinity maturation of vaccine induced pAb responses at component level and enhanced resolution of heterogeneity in avidity when antigen-binding fragments (Fab) are used instead of polyclonal IgG antibodies. The utility of PAART can be manifold in examining circulating pAb characteristics and could inform vaccine strategies aimed to guide the host humoral immune response.
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van der Velden FJS, de Vries G, Martin A, Lim E, von Both U, Kolberg L, Carrol ED, Khanijau A, Herberg JA, De T, Galassini R, Kuijpers TW, Martinón-Torres F, Rivero-Calle I, Vermont CL, Hagedoorn NN, Pokorn M, Pollard AJ, Schlapbach LJ, Tsolia M, Elefhteriou I, Yeung S, Zavadska D, Fink C, Voice M, Zenz W, Kohlmaier B, Agyeman PKA, Usuf E, Secka F, de Groot R, Levin M, van der Flier M, Emonts M. Febrile illness in high-risk children: a prospective, international observational study. Eur J Pediatr 2023; 182:543-554. [PMID: 36243780 PMCID: PMC9899189 DOI: 10.1007/s00431-022-04642-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 09/21/2022] [Accepted: 09/30/2022] [Indexed: 02/07/2023]
Abstract
To assess and describe the aetiology and management of febrile illness in children with primary or acquired immunodeficiency at high risk of serious bacterial infection, as seen in emergency departments in tertiary hospitals. Prospective data on demographics, presenting features, investigations, microbiology, management, and outcome of patients within the 'Biomarker Validation in HR patients' database in PERFORM, were analysed. Immunocompromised children (< 18 years old) presented to fifteen European hospitals in nine countries, and one Gambian hospital, with fever or suspected infection and clinical indication for blood investigations. Febrile episodes were assigned clinical phenotypes using the validated PERFORM algorithm. Logistic regression was used to assess the effect size of predictive features of proven/presumed bacterial or viral infection. A total of 599 episodes in 482 children were analysed. Seventy-eight episodes (13.0%) were definite bacterial, 67 episodes probable bacterial (11.2%), and 29 bacterial syndrome (4.8%). Fifty-five were definite viral (9.2%), 49 probable viral (8.2%), and 23 viral syndrome (3.8%). One hundred ninety were unknown bacterial or viral infections (31.7%), and 108 had inflammatory or other non-infectious causes of fever (18.1%). Predictive features of proven/presumed bacterial infection were ill appearance (OR 3.1 (95% CI 2.1-4.6)) and HIV (OR 10.4 (95% CI 2.0-54.4)). Ill appearance reduced the odds of having a proven/presumed viral infection (OR 0.5 (95% CI 0.3-0.9)). A total of 82.1% had new empirical antibiotics started on admission (N = 492); 94.3% proven/presumed bacterial (N = 164), 66.1% proven/presumed viral (N = 84), and 93.2% unknown bacterial or viral infections (N = 177). Mortality was 1.9% (N = 11) and 87.1% made full recovery (N = 522). Conclusion: The aetiology of febrile illness in immunocompromised children is diverse. In one-third of cases, no cause for the fever will be identified. Justification for standard intravenous antibiotic treatment for every febrile immunocompromised child is debatable, yet effective. Better clinical decision-making tools and new biomarkers are needed for this population. What is Known: • Immunosuppressed children are at high risk for morbidity and mortality of serious bacterial and viral infection, but often present with fever as only clinical symptom. • Current diagnostic measures in this group are not specific to rule out bacterial infection, and positivity rates of microbiological cultures are low. What is New: • Febrile illness and infectious complications remain a significant cause of mortality and morbidity in HR children, yet management is effective. • The aetiology of febrile illness in immunocompromised children is diverse, and development of pathways for early discharge or cessation of intravenous antibiotics is debatable, and requires better clinical decision-making tools and biomarkers.
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Huo J, Dijokaite-Guraliuc A, Liu C, Zhou D, Ginn HM, Das R, Supasa P, Selvaraj M, Nutalai R, Tuekprakhon A, Duyvesteyn HME, Mentzer AJ, Skelly D, Ritter TG, Amini A, Bibi S, Adele S, Johnson SA, Paterson NG, Williams MA, Hall DR, Plowright M, Newman TAH, Hornsby H, de Silva TI, Temperton N, Klenerman P, Barnes E, Dunachie SJ, Pollard AJ, Lambe T, Goulder P, Fry EE, Mongkolsapaya J, Ren J, Stuart DI, Screaton GR. A delicate balance between antibody evasion and ACE2 affinity for Omicron BA.2.75. Cell Rep 2023; 42:111903. [PMID: 36586406 PMCID: PMC9747698 DOI: 10.1016/j.celrep.2022.111903] [Citation(s) in RCA: 35] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 11/05/2022] [Accepted: 12/08/2022] [Indexed: 12/23/2022] Open
Abstract
Variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have caused successive global waves of infection. These variants, with multiple mutations in the spike protein, are thought to facilitate escape from natural and vaccine-induced immunity and often increase in affinity for ACE2. The latest variant to cause concern is BA.2.75, identified in India where it is now the dominant strain, with evidence of wider dissemination. BA.2.75 is derived from BA.2 and contains four additional mutations in the receptor-binding domain (RBD). Here, we perform an antigenic and biophysical characterization of BA.2.75, revealing an interesting balance between humoral evasion and ACE2 receptor affinity. ACE2 affinity for BA.2.75 is increased 9-fold compared with BA.2; there is also evidence of escape of BA.2.75 from immune serum, particularly that induced by Delta infection, which may explain the rapid spread in India, where where there is a high background of Delta infection. ACE2 affinity appears to be prioritized over greater escape.
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Fidler S, Fox J, Tipoe T, Longet S, Tipton T, Abeywickrema M, Adele S, Alagaratnam J, Ali M, Aley PK, Aslam S, Balasubramanian A, Bara A, Bawa T, Brown A, Brown H, Cappuccini F, Davies S, Fowler J, Godfrey L, Goodman AL, Hilario K, Hackstein CP, Mathew M, Mujadidi YF, Packham A, Petersen C, Plested E, Pollock KM, Ramasamy MN, Robinson H, Robinson N, Rongkard P, Sanders H, Serafimova T, Spence N, Waters A, Woods D, Zacharopoulou P, Barnes E, Dunachie S, Goulder P, Klenerman P, Winston A, Hill AVS, Gilbert SC, Carroll M, Pollard AJ, Lambe T, Ogbe A, Frater J. Booster Vaccination Against SARS-CoV-2 Induces Potent Immune Responses in People With Human Immunodeficiency Virus. Clin Infect Dis 2023; 76:201-209. [PMID: 36196614 PMCID: PMC9619587 DOI: 10.1093/cid/ciac796] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 08/23/2022] [Accepted: 09/28/2022] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND People with human immunodeficiency virus (HIV) on antiretroviral therapy (ART) with good CD4 T-cell counts make effective immune responses following vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). There are few data on longer term responses and the impact of a booster dose. METHODS Adults with HIV were enrolled into a single arm open label study. Two doses of ChAdOx1 nCoV-19 were followed 12 months later by a third heterologous vaccine dose. Participants had undetectable viraemia on ART and CD4 counts >350 cells/µL. Immune responses to the ancestral strain and variants of concern were measured by anti-spike immunoglobulin G (IgG) enzyme-linked immunosorbent assay (ELISA), MesoScale Discovery (MSD) anti-spike platform, ACE-2 inhibition, activation induced marker (AIM) assay, and T-cell proliferation. FINDINGS In total, 54 participants received 2 doses of ChAdOx1 nCoV-19. 43 received a third dose (42 with BNT162b2; 1 with mRNA-1273) 1 year after the first dose. After the third dose, total anti-SARS-CoV-2 spike IgG titers (MSD), ACE-2 inhibition, and IgG ELISA results were significantly higher compared to Day 182 titers (P < .0001 for all 3). SARS-CoV-2 specific CD4+ T-cell responses measured by AIM against SARS-CoV-2 S1 and S2 peptide pools were significantly increased after a third vaccine compared to 6 months after a first dose, with significant increases in proliferative CD4+ and CD8+ T-cell responses to SARS-CoV-2 S1 and S2 after boosting. Responses to Alpha, Beta, Gamma, and Delta variants were boosted, although to a lesser extent for Omicron. CONCLUSIONS In PWH receiving a third vaccine dose, there were significant increases in B- and T-cell immunity, including to known variants of concern (VOCs).
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Thompson KM, Lauring AS, Pollard AJ, Andino R, Bandyopadhyay AS, Berkley S, Bhutta ZA, Routh J, Benn CS. Polio eradication: Addressing the hurdles on the last mile. Cell 2023; 186:1-4. [PMID: 36608647 DOI: 10.1016/j.cell.2022.12.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 12/05/2022] [Accepted: 12/09/2022] [Indexed: 01/07/2023]
Abstract
1988, the World Health Assembly committed to eradicate poliomyelitis, a viral disease that can cause permanent paralysis. Today, only type 1 of the three wild poliovirus types remains circulating in limited geographic areas following widespread use of different poliovirus vaccines. While we are close to zero new cases of wild polio, it is a fragile situation, and there are many remaining and new hurdles to overcome. Here, experts discuss how to address them.
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Paton KR, Despotelis K, Kumar N, Turner P, Pollard AJ. On the use of Raman spectroscopy to characterize mass-produced graphene nanoplatelets. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2023; 14:509-521. [PMID: 37152472 PMCID: PMC10155622 DOI: 10.3762/bjnano.14.42] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 04/04/2023] [Indexed: 05/09/2023]
Abstract
Raman spectroscopy is one of the most common methods to characterize graphene-related 2D materials, providing information on a wide range of physical and chemical properties. Because of typical sample inhomogeneity, Raman spectra are acquired from several locations across a sample, and analysis is carried out on the averaged spectrum from all locations. This is then used to characterize the "quality" of the graphene produced, in particular the level of exfoliation for top-down manufactured materials. However, these have generally been developed using samples prepared with careful separation of unexfoliated materials. In this work we assess these metrics when applied to non-ideal samples, where unexfoliated graphite has been deliberately added to the exfoliated material. We demonstrate that previously published metrics, when applied to averaged spectra, do not allow the presence of this unexfoliated material to be reliably detected. Furthermore, when a sufficiently large number of spectra are acquired, it is found that by processing and classifying individual spectra, rather than the averaged spectrum, it is possible to identify the presence of this material in the sample, although quantification of the amount remains approximate. We therefore recommend this approach as a robust methodology for reliable characterization of mass-produced graphene-related 2D materials using confocal Raman spectroscopy.
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Mentzer AJ, O'Connor D, Bibi S, Chelysheva I, Clutterbuck EA, Demissie T, Dinesh T, Edwards NJ, Felle S, Feng S, Flaxman AL, Karp-Tatham E, Li G, Liu X, Marchevsky N, Godfrey L, Makinson R, Bull MB, Fowler J, Alamad B, Malinauskas T, Chong AY, Sanders K, Shaw RH, Voysey M, Snape MD, Pollard AJ, Lambe T, Knight JC. Human leukocyte antigen alleles associate with COVID-19 vaccine immunogenicity and risk of breakthrough infection. Nat Med 2023; 29:147-157. [PMID: 36228659 PMCID: PMC9873562 DOI: 10.1038/s41591-022-02078-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Accepted: 10/07/2022] [Indexed: 02/01/2023]
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine immunogenicity varies between individuals, and immune responses correlate with vaccine efficacy. Using data from 1,076 participants enrolled in ChAdOx1 nCov-19 vaccine efficacy trials in the United Kingdom, we found that inter-individual variation in normalized antibody responses against SARS-CoV-2 spike and its receptor-binding domain (RBD) at 28 days after first vaccination shows genome-wide significant association with major histocompatibility complex (MHC) class II alleles. The most statistically significant association with higher levels of anti-RBD antibody was HLA-DQB1*06 (P = 3.2 × 10-9), which we replicated in 1,677 additional vaccinees. Individuals carrying HLA-DQB1*06 alleles were less likely to experience PCR-confirmed breakthrough infection during the ancestral SARS-CoV-2 virus and subsequent Alpha variant waves compared to non-carriers (hazard ratio = 0.63, 0.42-0.93, P = 0.02). We identified a distinct spike-derived peptide that is predicted to bind differentially to HLA-DQB1*06 compared to other similar alleles, and we found evidence of increased spike-specific memory B cell responses in HLA-DQB1*06 carriers at 84 days after first vaccination. Our results demonstrate association of HLA type with Coronavirus Disease 2019 (COVID-19) vaccine antibody response and risk of breakthrough infection, with implications for future vaccine design and implementation.
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van der Velden FJS, de Vries G, Martin A, Lim E, von Both U, Kolberg L, Carrol ED, Khanijau A, Herberg JA, De T, Galassini R, Kuijpers TW, Martinón-Torres F, Rivero-Calle I, Vermont CL, Hagedoorn NN, Pokorn M, Pollard AJ, Schlapbach LJ, Tsolia M, Elefhteriou I, Yeung S, Zavadska D, Fink C, Voice M, Zenz W, Kohlmaier B, Agyeman PKA, Usuf E, Secka F, de Groot R, Levin M, van der Flier M, Emonts M, Cunnington A, De T, Herberg J, Kaforou M, Wright V, Baumard L, Bellos E, D’Souza G, Galassini R, Habgood-Coote D, Hamilton S, Hoggart C, Hourmat S, Jackson H, Maconochie I, Menikou S, Lin N, Nichols S, Nijman R, Powell O, Pena Paz I, Shah P, Shen CF, Vito O, Wilson C, Abdulla A, Ali L, Darnell S, Jorgensen R, Mustafa S, Persand S, Stevens MM, Kim N, Kim E, Fidler K, Dudley J, Richmond V, Tavliavini E, Shen CF, Liu CC, Wang SM, Martinón-Torres F, Salas A, González FÁ, Farto CB, Barral-Arca R, Castro MB, Bello X, García MB, Carnota S, Cebey-López M, Curras-Tuala MJ, Suárez CD, Vicente LG, Gómez-Carballa A, Rial JG, Iglesias PL, Martinón-Torres F, Martinón-Torres N, Sánchez JMM, Pérez BM, Pardo-Seco J, Rodríguez LP, Pischedda S, Vázquez SR, Calle IR, Rodríguez-Tenreiro C, Redondo-Collazo L, Ora MS, Salas A, Fernández SS, Trasorras CS, Iglesias MV, Zavadska D, Balode A, Bārzdiņa A, Deksne D, Gardovska D, Grāvele D, Grope I, Meiere A, Nokalna I, Pavāre J, Pučuka Z, Selecka K, Rudzāte A, Svile D, Urbāne UN, Usuf E, Bojang K, Zaman SMA, Secka F, Anderson S, Sarr AR, Saidykhan M, Darboe S, Ceesay S, D’alessandro U, Moll HA, Vermont CL, Borensztajn DM, Hagedoorn NN, Tan C, Zachariasse J, Dik W, Agyeman PKA, Berger C, Giannoni E, Stocker M, Posfay-Barbe KM, Heininger U, Bernhard-Stirnemann S, Niederer-Loher A, Kahlert CR, Natalucci G, Relly C, Riedel T, Aebi C, Schlapbach LJ, Carrol ED, Cocklin E, Jennings R, Johnston J, Khanijau A, Leigh S, Lewis-Burke N, Newall K, Romaine S, Tsolia M, Eleftheriou I, Tambouratzi M, Marmarinos A, Xagorari M, Syggelou K, Fink C, Voice M, Calvo-Bado L, Zenz W, Kohlmaier B, Schweintzger NA, Sagmeister MG, Kohlfürst DS, Zurl C, Binder A, Hösele S, Leitner M, Pölz L, Rajic G, Bauchinger S, Baumgart H, Benesch M, Ceolotto A, Eber E, Gallistl S, Gores G, Haidl H, Hauer A, Hude C, Keldorfer M, Krenn L, Pilch H, Pfleger A, Pfurtscheller K, Nordberg G, Niedrist T, Rödl S, Skrabl-Baumgartner A, Sperl M, Stampfer L, Strenger V, Till H, Trobisch A, Löffler S, Yeung S, Dewez JE, Hibberd M, Bath D, Miners A, Nijman R, Fitchett E, de Groot R, van der Flier M, de Jonge MI, van Aerde K, Alkema W, van den Broek B, Gloerich J, van Gool AJ, Henriet S, Huijnen M, Philipsen R, Willems E, Gerrits G, van Leur M, Heidema J, de Haan L, Miedema C, Neeleman C, Obihara C, Tramper-Stranders G, Pollard AJ, Kandasamy R, Paulus S, Carter MJ, O’Connor D, Bibi S, Kelly DF, Gurung M, Thorson S, Ansari I, Murdoch DR, Shrestha S, Oliver Z, Emonts M, Lim E, Valentine L, Allen K, Bell K, Chan A, Crulley S, Devine K, Fabian D, King S, McAlinden P, McDonald S, McDonnell A, Pickering A, Thomson E, Wood A, Wallia D, Woodsford P, Baxter F, Bell A, Rhodes M, Agbeko R, Mackerness C, Baas B, Kloosterhuis L, Oosthoek W, Arif T, Bennet J, Collings K, van der Giessen I, Martin A, Rashid A, Rowlands E, de Vries G, van der Velden F, Soon J, Valentine L, Martin M, Mistry R, von Both U, Kolberg L, Zwerenz M, Buschbeck J, Bidlingmaier C, Binder V, Danhauser K, Haas N, Griese M, Feuchtinger T, Keil J, Kappler M, Lurz E, Muench G, Reiter K, Schoen C, Mallet F, Brengel-Pesce K, Pachot A, Mommert M, Pokorn M, Kolnik M, Vincek K, Srovin TP, Bahovec N, Prunk P, Osterman V, Avramoska T, Kuijpers T, Jongerius I, van den Berg JM, Schonenberg D, Barendregt AM, Pajkrt D, van der Kuip M, van Furth AM, Sprenkeler E, Zandstra J, van Mierlo G, Geissler J. Correction to: Febrile illness in high-risk children: a prospective, international observational study. Eur J Pediatr 2023; 182:555-556. [PMID: 36689005 PMCID: PMC9899168 DOI: 10.1007/s00431-022-04788-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Iro MA, Rollier CS, Irani SR, Sadarangani M, Al-Diwani A, Pollard AJ, Clutterbuck EA. Regulatory T cell profiles in patients with N-methyl-ᴅ-aspartate receptor-antibody encephalitis. ENCEPHALITIS 2023; 3:15-23. [PMID: 37469716 PMCID: PMC10295821 DOI: 10.47936/encephalitis.2022.00052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 09/24/2022] [Accepted: 09/30/2022] [Indexed: 07/21/2023] Open
Abstract
Purpose Purpose Regulatory T cells (Tregs) have been implicated in the pathogenesis of several autoimmune disorders and used in adoptive cell transfer therapies. Neither have been explored in patients with autoimmune encephalitis where treated patient outcomes remain suboptimal with frequent relapses. Here, to identify new treatment strategies for autoimmune encephalitis, we sought to evaluate the proportion of circulating Tregs and Treg subpopulations in peripheral blood of patients with N-methyl-ᴅ-aspartate receptor-antibody encephalitis (NMDAR-Ab-E) and compared this with healthy controls. Methods We compared the phenotype of peripheral blood Tregs in four adult NMDAR-Ab-E patients and four age- and sex-matched healthy controls using an 11-color flow cytometry assay panel for characterization of Tregs (CD4+ CD25+ FoxP3+) cells into naïve (chemokine receptor [CCR] 7+ CD45RA+), central memory (CCR7+ CD45RA-), and effector memory (CCR7- CD45RA-) cells. We also examined and compared the expression of the CCR6 by circulating Tregs and the respective Treg subpopulations between the study groups. Results The proportion of circulating Tregs was similar between patients with NMDAR-Ab-E and healthy controls but the proportion of naïve Tregs was lower in NMDAR-Ab-E patients (p = 0.0026). Additionally, the frequency of circulating effector memory Tregs was higher, and the proportion of circulating effector memory Tregs expressing CCR6 was lower, in NMDAR-Ab-E patients compared with healthy controls (p = 0.0026). Conclusion Altered Treg homeostasis may be a feature of patients with NMDAR-Ab-E. Future studies with larger samples are warranted to validate these findings.
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Brown P, Waite F, Larkin M, Lambe S, McShane H, Pollard AJ, Freeman D. " It seems impossible that it's been made so quickly": a qualitative investigation of concerns about the speed of COVID-19 vaccine development and how these may be overcome. Hum Vaccin Immunother 2022; 18:2004808. [PMID: 35172678 PMCID: PMC8928812 DOI: 10.1080/21645515.2021.2004808] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 11/03/2021] [Accepted: 11/08/2021] [Indexed: 11/17/2022] Open
Abstract
The speed of COVID-19 vaccine development has been identified as a central concern contributing to hesitancy in acceptance. We conducted qualitative interviews to gain a greater understanding into these concerns and to identify what might address them. Twelve qualitative interviews were conducted with participants identifying as hesitant for COVID-19 vaccination and reporting concern about the speed of vaccine development. Interpretative Phenomenological Analysis (IPA) was used. Concerns about speed comprised the linked themes of i) difficulty understanding the pace, and, ii) worry about the implications for vaccine safety. Uncertainties concerning the pandemic led to a notable desire for credible and understandable information regarding the vaccines, which many participants felt was not available. Four routes to resolving uncertainty about whether to be vaccinated were identified. First, waiting for more information about the vaccines, such as about their contents and impact on transmission. Second, a growing perception that the vaccines must be safe given the large numbers already vaccinated. Third, viewing the vaccines as necessary - even if unappealing - for ending the pandemic. Finally, a feeling that there would be no choice but to have a vaccine. Examples of what might reduce hesitancy were given, including interviews with vaccine developers and knowing others of similar age having safely been vaccinated. The pace of development broke expectations set earlier in the pandemic. This was interpreted negatively due to a perceived lack of credible information. Most participants could envisage ways their concerns could be resolved, enough for them to have a vaccine.
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