Publications by authors named "Andrew J. Pollard"
Objectives: To identify demographic, clinical and immunological factors associated with adverse COVID-19 outcomes.
Methods: A large randomised controlled trial of ChAdOx1 nCoV-19 was undertaken in Brazil. Participants were randomised 1:1 either to receive ChAdOx1 nCov-19 or to a control group.
Respiratory syncytial virus (RSV) is the leading cause of infant respiratory infections and hospitalizations. To investigate the relationship between the respiratory microbiome and RSV infection, we sequence nasopharyngeal samples from a birth cohort and a pediatric case-control study (Respiratory Syncytial virus Consortium in Europe [RESCEU]). 1,537 samples are collected shortly after birth ("baseline"), during RSV infection and convalescence, and from healthy controls.
View Article and Find Full Text PDFArticle Synopsis
- Twisted two-dimensional (2D) material heterostructures allow researchers to explore unique physical phenomena, especially at small twist angles where crystals rearrange themselves.
- Understanding these complex materials requires advanced imaging techniques to visualize the local configurations, which can vary due to disorder.
- The study presents an effective method using electron channeling contrast imaging (ECCI) to non-destructively visualize these domains in twisted transition metal dichalcogenide (TMD) heterostructures, even under encapsulation layers, enhancing insight into their properties.
Despite significant progress in vaccine research, the level of protection provided by vaccination can vary significantly across individuals. As a result, understanding immunologic variation across individuals in response to vaccination is important for developing next-generation efficacious vaccines. Accurate outcome prediction and identification of predictive biomarkers would represent a significant step towards this goal.
View Article and Find Full Text PDFTyphoid and Paratyphoid fever cause a global health burden, especially for the children of Southern Asia. The impact of the disease is further exacerbated by the dramatic increase of antimicrobial resistance. While vaccines against Typhi have been developed and successfully introduced, an effective vaccine targeting Paratyphi A is still lacking.
View Article and Find Full Text PDFIntroduction: Respiratory syncytial virus (RSV) causes acute respiratory tract infection (ARTI) and reinfects adults throughout life, posing a risk for hospitalization in older adults (>60 years) with frailty and comorbidities.
Methods: To investigate serum and mucosal antibodies for protection against RSV infections, baseline serum samples were compared for RSV-pre- and -post-fusion (F) binding, and RSV-A2 neutralizing IgG antibodies between symptomatic RSV-ARTI ( = 30), non-RSV (RSV negative) ARTI ( = 386), and no ARTI ( = 338). Mucosal RSV-pre-F IgA and IgG levels, as well as serum RSV-G IgG antibodies, were analyzed to determine their association with protection from symptomatic RSV-ARTI in a subset study.
Article Synopsis
- The demand for graphene-related 2D materials (GR2Ms) is increasing, so the industry needs reliable, easy-to-use quality measurement methods for production.
- The paper highlights the use of hydrogen nuclear magnetic resonance (NMR) relaxation and Raman spectroscopy as effective techniques for real-time quality monitoring of GR2Ms.
- NMR relaxation can deliver results in under a minute, while Raman spectroscopy offers continuous data collection during production, improving overall quality control compared to traditional lab methods.
Article Synopsis
- - The study aimed to understand how long the protection from the typhoid conjugate vaccine (TCV) lasts by extending research from the TyVAC trial in Bangladesh to 5 years post-vaccination.
- - It found that children who received the TCV between 2018-2019 had a significantly higher risk of contracting typhoid compared to those vaccinated more recently, indicating that vaccine effectiveness declines over time.
- - The research showed an estimated vaccine effectiveness of only 50% in the 3-5 year period after vaccination, highlighting the need for further studies on booster doses to maintain immunity.
Objectives: To describe the development, validation and reliability of the Oxford Vaccine Hesitancy Scale (OVHS), a new instrument to assess vaccine hesitancy in the general population.
Design: Cross-sectional validation study.
Setting: Internet-based study with participants in the UK and USA.
Article Synopsis
- Respiratory syncytial virus (RSV) commonly causes severe respiratory infections, especially in infants and vulnerable populations, and predicting its clinical course can be challenging as many severe cases occur in healthy individuals.
- Recent advancements in RSV vaccines and monoclonal antibodies make it crucial to identify high-risk people who would benefit from preventive treatments.
- Research using animal models has revealed complex immune responses to RSV, suggesting that specific immune system components and genetic markers may help in predicting disease severity and identifying at-risk patients for future studies.
Roles and responsibilities of participants, researchers, and the media in the communication of vaccine trials: Experience from the United Kingdom's first COVID-19 vaccine trial.
Vaccine
December 2024
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.
Article Synopsis
- The study investigates the role of circulating T follicular helper cells (cT) in the immune response to Typhi infection, using data from a controlled human infection model.
- Participants who did not develop typhoid disease (NoTD) showed higher frequencies of specific cT subsets (cT2 and cT17) compared to those who developed the disease (TD), particularly a week post-challenge.
- The findings suggest that these cT subsets are associated with the production of anti-Typhi antibodies and could be crucial for developing effective vaccines against typhoid disease.
Article Synopsis
- RSV is a significant cause of infant mortality and poses health risks for older adults, prompting the development of various vaccines and treatments, including a protein-based maternal vaccine and monoclonal antibodies (mAb) specifically for infants.* -
- High-income countries have seen public health benefits from using nirsevimab, and several vaccines for older adults have also been approved, with ongoing clinical trials for multiple vaccine types targeting different age groups.* -
- There's a need to address disparities in vaccine access, especially in low- and middle-income countries, with plans to advance RSV vaccination efforts globally in the near future.*
Article Synopsis
- A Controlled Human Infection Model (CHIM) with wild-type Salmonella Typhi was set up to study immunity development, revealing that about 55% of volunteers met typhoid diagnosis criteria after infection.
- Intestinal macrophages, which play a crucial role in gut defense, are derived from circulating monocytes rather than tissue-resident progenitors, making them unique compared to macrophages in other organs.
- Changes in circulating monocytes were tracked post-infection, showing that typhoid diagnosis participants had increased activation markers, indicating a heightened immune response, and upregulated molecules to interact with both bacterial antigens and adaptive immune cells.
Article Synopsis
- Controlled human infection model (CHIM) studies involve intentionally exposing healthy volunteers to pathogens, aiding in vaccine development by evaluating efficacy and understanding disease processes in a controlled setting.
- These studies help identify immunological correlates of protection (CoP), which are critical for accelerating the development of vaccines, especially against invasive infections like typhoid and paratyphoid fever.
- While CHIM has advanced knowledge about Typhi and its vaccine, there is still limited understanding of CoP for Paratyphi A and non-typhoidal Salmonella infections, emphasizing the need for ongoing research in this area.
Objectives: We evaluated the extent of virus heterogeneity in PeV infected infants in the UK, Canada and Australia.
Methods: Samples were collected from PeV infected infants during 2013-16. Next generation sequencing was used to obtain sequencing data and construct phylogenetic trees based on analysis of the VP1 region.
Background: For pathogens which cause infections that present asymptomatically, evaluating vaccine efficacy (VE) against asymptomatic infection is important for understanding a vaccine's potential epidemiological impact. Regular testing for subclinical infections is a potentially valuable strategy but its success hinges on participant adherence and minimising false positives. This paper describes the implementation and adherence to weekly testing in a COVID-19 vaccine trial.
View Article and Find Full Text PDFBackground: Vaccination of infants with pneumococcal conjugate vaccines is recommended by the World Health Organization. Evidence is mixed regarding the differences in immunogenicity and efficacy of the different pneumococcal vaccines.
Objectives: The primary objective was to compare the immunogenicity of pneumococcal conjugate vaccine-10 versus pneumococcal conjugate vaccine-13.
Article Synopsis
- Outbreaks of Ebolaviruses, like Sudanvirus in Uganda in 2022, highlight the need for vaccines that target more than just the Zaire ebolavirus, which is currently the only one in use.
- A new vaccine regimen, Ad26.ZEBOV/MVA-BN-Filo, was developed and tested in the EBL2001 clinical trial, aiming to enhance immunity against various Ebolaviruses.
- Researchers sequenced B cell receptors from trial participants and created a database of Ebolavirus-specific antibodies, revealing important patterns in immune responses and demonstrating the potential for computational techniques to analyze immune repertoires effectively.
Article Synopsis
- Enteric fever, caused by Salmonella enterica serovars Typhi and Paratyphi A, poses a significant public health issue due to rising antimicrobial resistance, complicating treatment options and worsening health outcomes.
- *The study sequenced bacteria samples from blood cultures of febrile patients in urban sites of Dhaka (Bangladesh), Kathmandu (Nepal), and Blantyre (Malawi) to analyze their genetic characteristics and resistance mechanisms.
- *Findings revealed that different genotypes of S. Typhi were present across the sites, with high rates of multidrug resistance in Blantyre and Dhaka but not in Kathmandu, highlighting diverse transmission dynamics and resistance patterns.
Immunogenicity and safety of beta variant COVID-19 vaccine AZD2816 and AZD1222 (ChAdOx1 nCoV-19) as primary-series vaccination for previously unvaccinated adults in Brazil, South Africa, Poland, and the UK: a randomised, partly double-blinded, phase 2/3 non-inferiority immunobridging study.
Lancet Microbe
August 2024
Article Synopsis
- AZD2816 is a variant-specific COVID-19 vaccine designed to improve immunity against the SARS-CoV-2 beta variant while still resembling the original AZD1222 vaccine.
- The study involved unvaccinated adults in a randomized, multinational trial across several countries, primarily assessing the safety and effectiveness of administering different schedules of the two vaccines over a period of 180 days.
- Results indicated comparable safety profiles and immune responses to both vaccines, with slight variations in the rates of adverse events and antibody responses among the different groups.
Background: Carriage studies are an efficient means for assessing pneumococcal conjugate vaccine effect in settings where pneumococcal disease surveillance programmes are not well established. In this study the effect of 10-valent pneumococcal conjugate vaccine (PCV10) introduction on pneumococcal carriage and density among Nepalese children using a bacterial microarray and qPCR was examined.
Methods: PCV10 was introduced into the Nepalese infant immunisation schedule in August 2015.