Publications by authors named "Ka Fenton"

Background: The risk of onwards HIV transmission is strongly influenced by the interval between HIV infection and its diagnosis. The SELPHI trial examined whether this interval could be reduced by offering free HIV self-testing kits to men-who-have-sex with-men (MSM).

Setting: Internet-based RCT of MSM aged ≥16 years, resident in England/Wales, recruited via sexual and social networking sites.

View Article and Find Full Text PDF

The recent outbreak of Marburg virus (MARV) in Rwanda underscores the need for effective countermeasures against this highly fatal pathogen, with case fatality rates reaching 90%. Currently, no vaccines or approved treatments exist for MARV infection, distinguishing it from related viruses like Ebola. Our research demonstrates that the oral drug obeldesivir (ODV), a nucleoside analog prodrug, shows promising antiviral activity against filoviruses in vitro and offers significant protection in animal models.

View Article and Find Full Text PDF

Tertiary lymphoid structures (TLSs) are formed in tissues targeted by chronic inflammation processes, such as infection and autoimmunity. In Sjögren's disease, the organization of immune cells into TLS is an important part of disease progression. Here, we investigated the dynamics of tissue resident macrophages in the induction and expansion of salivary gland TLS.

View Article and Find Full Text PDF
Article Synopsis
  • The pathogenesis of systemic lupus erythematosus (SLE) is significantly influenced by toll-like receptors (TLRs), especially TLR7, TLR8, and TLR9, with TLR7 overexpression linked to more severe cases of SLE.
  • Genetic factors, including the location of these receptors on the X-chromosome, contribute to SLE's higher prevalence in females, while the absence of TLR8 and TLR9 can worsen TLR7's effects, leading to increased disease severity.
  • Research suggests that targeting TLRs, alongside identifying specific markers for age-associated B cells (ABCs) which produce autoantibodies, could lead to new therapeutic approaches, with existing treatments
View Article and Find Full Text PDF

Obeldesivir (ODV, GS-5245) is an orally administered prodrug of the parent nucleoside of remdesivir (RDV) and is presently in phase 3 trials for COVID-19 treatment. In this work, we show that ODV and its circulating parent nucleoside metabolite, GS-441524, have similar in vitro antiviral activity against filoviruses, including Marburg virus, Ebola virus, and Sudan virus (SUDV). We also report that once-daily oral ODV treatment of cynomolgus monkeys for 10 days beginning 24 hours after SUDV exposure confers 100% protection against lethal infection.

View Article and Find Full Text PDF

Lassa fever (LF) is an acute viral illness that causes thousands of deaths annually in West Africa. There are currently no Lassa virus (LASV) vaccines or antivirals approved for human use. Recently, we showed that combinations of broadly neutralizing human monoclonal antibodies (BNhuMAbs) known as Arevirumab-2 or Arevirumab-3 protected up to 100% of cynomolgus macaques against challenge with diverse lineages of LASV when treatment was initiated at advanced stages of disease.

View Article and Find Full Text PDF

Lassa virus (LASV) is a World Health Organization (WHO) priority pathogen that causes high morbidity and mortality. Recently, we showed that a combination of three broadly neutralizing human monoclonal antibodies known as Arevirumab-3 (8.9F, 12.

View Article and Find Full Text PDF

As part of the non-clinical safety package characterizing bamlanivimab (SARS-CoV-2 neutralizing monoclonal antibody), the risk profile for antibody-dependent enhancement of infection (ADE) was evaluated in vitro and in an African green monkey (AGM) model of COVID-19. In vitro ADE assays in primary human macrophage, Raji, or THP-1 cells were used to evaluate enhancement of viral infection. Bamlanivimab binding to C1q, FcR, and cell-based effector activity was also assessed.

View Article and Find Full Text PDF

Background: In the UK, the number of new HIV diagnoses among gay and bisexual men who have sex with men (GBMSM) has decreased substantially. We aimed to understand the contribution of different interventions in reducing HIV incidence so far; to estimate future HIV incidence with continuation of current policies and with further scaling up of current interventions; and to estimate the maximum additional annual cost that should be spent towards these interventions for them to offer value for money.

Methods: We calibrated a dynamic, individual-based, stochastic simulation model, the HIV Synthesis Model, to multiple sources of data on HIV among GBMSM aged 15 years or older in the UK.

View Article and Find Full Text PDF

Background: Marburg virus (MARV) has caused numerous sporadic outbreaks of severe hemorrhagic fever in humans. Human case fatality rates of Marburg virus disease (MVD) outbreaks range from 20% to 90%. Viral genotypes of MARV can differ by over 20%, suggesting variable virulence between lineages may accompany this genetic divergence.

View Article and Find Full Text PDF

There are no approved treatments for Lassa fever (LF), which is responsible for thousands of deaths each year in West Africa. A major challenge in developing effective medical countermeasures against LF is the high diversity of circulating Lassa virus (LASV) strains with four recognized lineages and four proposed lineages. The recent resurgence of LASV in Nigeria caused by genetically distinct strains underscores this concern.

View Article and Find Full Text PDF

Marburg virus (MARV) causes a hemorrhagic fever disease in human and nonhuman primates with high levels of morbidity and mortality. Concerns about weaponization of aerosolized MARV have spurred the development of nonhuman primate (NHP) models of aerosol exposure. To address the potential threat of aerosol exposure, a monoclonal antibody that binds MARV glycoprotein was tested, MR186YTE, for its efficacy as a prophylactic.

View Article and Find Full Text PDF

There are several autoimmune and rheumatic diseases affecting different organs of the human body. Multiple sclerosis (MS) mainly affects brain, rheumatoid arthritis (RA) mainly affects joints, Type 1 diabetes (T1D) mainly affects pancreas, Sjogren's syndrome (SS) mainly affects salivary glands, while systemic lupus erythematosus (SLE) affects almost every organ of the body. Autoimmune diseases are characterized by production of autoantibodies, activation of immune cells, increased expression of pro-inflammatory cytokines, and activation of type I interferons.

View Article and Find Full Text PDF
Article Synopsis
  • Ebola virus (EBOV) is extremely dangerous, with high fatality rates, and while some viral proteins are known to impact its virulence, the exact role of the mucin-like domain (MLD) in disease is less understood.
  • Researchers created a version of EBOV without the MLD to study its effects on disease progression in ferrets, comparing it with the wild-type (WT) virus.
  • The study found no significant differences in growth, time to death, or clinical symptoms between the MLD-lacking virus and the WT virus, suggesting that the MLD is not crucial for the acute pathogenesis of Ebola virus disease (EVD) in ferrets.
View Article and Find Full Text PDF

Background: The primary route of infection by Ebola virus (EBOV) is through contact of mucosal surfaces. Few studies have explored infection of nonhuman primates (NHPs) via the oral mucosa, which is a probable portal of natural infection in humans.

Methods: To further characterize the pathogenesis of EBOV infection via the oral exposure route, we challenged cohorts of cynomolgus monkeys with low doses of EBOV variant Makona.

View Article and Find Full Text PDF

Background: The filovirus Bundibugyo virus (BDBV) causes severe disease with a mortality rate of approximately 20%-51%. The only licensed filovirus vaccine in the United States, Ervebo, consists of a recombinant vesicular stomatitis virus (rVSV) vector that expresses Ebola virus (EBOV) glycoprotein (GP). Ervebo was shown to rapidly protect against fatal Ebola disease in clinical trials; however, the vaccine is only indicated against EBOV.

View Article and Find Full Text PDF

Background: The family Filoviridae consists of several virus members known to cause significant mortality and disease in humans. Among these, Ebola virus (EBOV), Marburg virus (MARV), Sudan virus (SUDV), and Bundibugyo virus (BDBV) are considered the deadliest. The vaccine, Ervebo, was shown to rapidly protect humans against Ebola disease, but is indicated only for EBOV infections with limited cross-protection against other filoviruses.

View Article and Find Full Text PDF

Background: Highly pathogenic filoviruses such as Ebola virus (EBOV) hold capacity for delivery by artificial aerosols, and thus potential for intentional misuse. Previous studies have shown that high doses of EBOV delivered by small-particle aerosol cause uniform lethality in nonhuman primates (NHPs), whereas only a few small studies have assessed lower doses in NHPs.

Methods: To further characterize the pathogenesis of EBOV infection via small-particle aerosol, we challenged cohorts of cynomolgus monkeys with low doses of EBOV variant Makona, which may help define risks associated with small particle aerosol exposures.

View Article and Find Full Text PDF
Article Synopsis
  • Ebola virus (EBOV) primarily spreads through contact with infected body fluids, affecting mucosal surfaces, and previous studies have mostly used lethal routes such as intramuscular injection or aerosol exposure.
  • In new studies with cynomolgus macaques, higher doses of EBOV were lethal while lower doses led to survival in most cases, indicating that natural exposure routes might have different outcomes than previously tested methods.
  • The study found that those exposed to lower doses had delayed onset of disease and showed asymptomatic infections, suggesting potential natural immune barriers that could limit the spread of the virus among survivors.
View Article and Find Full Text PDF

The Marburg and Ebola filoviruses cause a severe, often fatal, disease in humans and nonhuman primates but have only subclinical effects in bats, including Egyptian rousettes, which are a natural reservoir of Marburg virus. A fundamental question is why these viruses are highly pathogenic in humans but fail to cause disease in bats. To address this question, we infected one cohort of Egyptian rousette bats with Marburg virus and another cohort with Ebola virus and harvested multiple tissues for mRNA expression analysis.

View Article and Find Full Text PDF

Background: High levels of HIV testing in men who have sex with men remain key to reducing the incidence of HIV. We aimed to assess whether the offer of a single, free HIV self-testing kit led to increased HIV diagnoses with linkage to care.

Methods: SELPHI was an internet-based, open-label, randomised controlled trial that recruited participants via sexual and social networking sites.

View Article and Find Full Text PDF

The emergence of the novel henipavirus, Langya virus, received global attention after the virus sickened over three dozen people in China. There is heightened concern that henipaviruses, as respiratory pathogens, could spark another pandemic, most notably the deadly Nipah virus (NiV). NiV causes near-annual outbreaks in Bangladesh and India and induces a highly fatal respiratory disease and encephalitis in humans.

View Article and Find Full Text PDF

Lassa virus (LASV) is recognized by the World Health Organization as one of the top five pathogens likely to cause a severe outbreak. A recent unprecedented resurgence of LASV in Nigeria caused by genetically diverse strains underscores the need for licensed medical countermeasures. Single-injection vaccines that can rapidly control outbreaks and confer long-term immunity are needed.

View Article and Find Full Text PDF

Due to its high mortality rate and continued re-emergence, Ebolavirus disease (EVD) continues to pose a serious threat to global health. A group of viruses within the genus causes this severe hemorrhagic disease in humans: Ebola virus (EBOV; species ), Sudan virus (SUDV; species ), Bundibugyo virus, and Taï Forest virus. EBOV and SUDV are associated with the highest case fatality rates.

View Article and Find Full Text PDF