There is need for effective and affordable vaccines against SARS-CoV-2 to tackle the ongoing pandemic. In this study, we describe a protein nanoparticle vaccine against SARS-CoV-2. The vaccine is based on the display of coronavirus spike glycoprotein receptor-binding domain (RBD) on a synthetic virus-like particle (VLP) platform, SpyCatcher003-mi3, using SpyTag/SpyCatcher technology. Low doses of RBD-SpyVLP in a prime-boost regimen induce a strong neutralising antibody response in mice and pigs that is superior to convalescent human sera. We evaluate antibody quality using ACE2 blocking and neutralisation of cell infection by pseudovirus or wild-type SARS-CoV-2. Using competition assays with a monoclonal antibody panel, we show that RBD-SpyVLP induces a polyclonal antibody response that recognises key epitopes on the RBD, reducing the likelihood of selecting neutralisation-escape mutants. Moreover, RBD-SpyVLP is thermostable and can be lyophilised without losing immunogenicity, to facilitate global distribution and reduce cold-chain dependence. The data suggests that RBD-SpyVLP provides strong potential to address clinical and logistic challenges of the COVID-19 pandemic.
Investigation into the pathogenesis of foot-and-mouth disease (FMD) has focused on the study of the disease in cattle with less emphasis on pigs, small ruminants and wildlife. 'Atypical' FMD-associated syndromes such as myocarditis, reproductive losses and chronic heat intolerance have also received little attention. Yet, all of these manifestations of FMD are reflections of distinct pathogenesis events. For example, naturally occurring porcinophilic strains and unique virus-host combinations that result in high-mortality outbreaks surely have their basis in molecular-, cellular- and tissue-level interactions between host and virus (i.e. pathogenesis). The goal of this review is to emphasize how the less commonly studied FMD syndromes and host species contribute to the overall understanding of pathogenesis and how extensive in vitro studies have contributed to our understanding of disease processes in live animals.
Clinical development of the COVID-19 vaccine candidate ChAdOx1 nCoV-19, a replication-deficient simian adenoviral vector expressing the full-length SARS-CoV-2 spike (S) protein was initiated in April 2020 following non-human primate studies using a single immunisation. Here, we compared the immunogenicity of one or two doses of ChAdOx1 nCoV-19 in both mice and pigs. Whilst a single dose induced antigen-specific antibody and T cells responses, a booster immunisation enhanced antibody responses, particularly in pigs, with a significant increase in SARS-CoV-2 neutralising titres.
Rapid, field-based diagnostic assays are desirable tools for the control of foot-and-mouth disease (FMD). Current approaches involve either; 1) Detection of FMD virus (FMDV) with immuochromatographic antigen lateral flow devices (LFD), which have relatively low analytical sensitivity, or 2) portable RT-qPCR that has high analytical sensitivity but is expensive. Loop-mediated isothermal amplification (LAMP) may provide a platform upon which to develop field based assays without these drawbacks. The objective of this study was to modify an FMDV-specific reverse transcription–LAMP (RT-LAMP) assay to enable detection of dual-labelled LAMP products with an LFD, and to evaluate simple sample processing protocols without nucleic acid extraction. The limit of detection of this assay was demonstrated to be equivalent to that of a laboratory based real-time RT-qPCR assay and to have a 10,000 fold higher analytical sensitivity than the FMDV-specific antigen LFD currently used in the field. Importantly, this study demonstrated that FMDV RNA could be detected from epithelial suspensions without the need for prior RNA extraction, utilising a rudimentary heat source for amplification. Once optimised, this RT-LAMP-LFD protocol was able to detect multiple serotypes from field epithelial samples, in addition to detecting FMDV in the air surrounding infected cattle, pigs and sheep, including pre-clinical detection. This study describes the development and evaluation of an assay format, which may be used as a future basis for rapid and low cost detection of FMDV. In addition it provides providing “proof of concept” for the future use of LAMP assays to tackle other challenging diagnostic scenarios encompassing veterinary and human health.
There is dire need for an effective and affordable vaccine against SARS-CoV-2 to tackle the ongoing pandemic. In this study, we describe a modular virus-like particle vaccine candidate displaying the SARS-CoV-2 spike glycoprotein receptor-binding domain (RBD) using SpyTag/SpyCatcher technology (RBD-SpyVLP). Low doses of RBD-SpyVLP in a prime-boost regimen induced a strong neutralising antibody response in mice and pigs that was superior to convalescent human sera. We evaluated antibody quality using ACE2 blocking and neutralisation of cell infection by pseudovirus or wild-type SARS-CoV-2. Using competition assays with a monoclonal antibody panel, we showed that RBD-SpyVLP induced a polyclonal antibody response that recognised all key epitopes on the RBD, reducing the likelihood of selecting neutralisation-escape mutants. The induction of potent and polyclonal antibody responses by RBD-SpyVLP provides strong potential to address clinical and logistic challenges of the COVID-19 pandemic. Moreover, RBD-SpyVLP is highly resilient, thermostable and can be lyophilised without losing immunogenicity, to facilitate global distribution and reduce cold-chain dependence.
A case of foot-and-mouth disease (fmd) on a cattle farm in Normandy, Surrey, was confirmed on Friday August 3, 2007, the first case in the uk since 2001. The infection was detected nearby on a second farm on August 6. On September 12, fmd was confirmed on a farm approximately 20 km from Normandy in Egham, and this was followed by cases on five more farms in that area in the next three weeks. The majority of the infected farms consisted of multiple beef cattle holdings in semi-urban areas. In total, 1578 animals were culled on the infected farms, and fmd virus infection was confirmed in 278 of them by the detection of viral antigen, genome or antibodies to the virus, or by clinical signs. This paper describes the findings from animal inspections on the infected farms, including the estimated ages of the fmd lesions and the numbers of animals infected. It also summarises the test results from samples taken for investigation, including the detection of preclinically viraemic animals by using real-time reverse transcriptase-pcr.
HighlightsFMDV A/ASIA/G-VII lineage has recently spread beyond the Indian sub-continent.Study evaluated the performance of a high potency polyvalent vaccine in cattle.A new vaccine strain should be developed which is tailored to the A/ASIA/G-VII lineage.
Laboratory animal models have provided valuable insight into foot-and-mouth disease virus (FMDV) pathogenesis in epidemiologically important target species. While not perfect, these models have delivered an accelerated time frame to characterize the immune responses in natural hosts and a platform to evaluate therapeutics and vaccine candidates at a reduced cost. Further expansion of these models in mice has allowed access to genetic mutations not available for target species, providing a powerful and versatile experimental system to interrogate the immune response to FMDV and to target more expensive studies in natural hosts. The purpose of this review is to describe commonly used FMDV infection models in laboratory animals and to cite examples of when these models have failed or successfully provided insight relevant for target species, with an emphasis on natural and vaccine-induced immunity.
IntroductionFoot-and-mouth disease virus (FMDV: family Picornaviridae; genus Aphthovirus) is known to naturally infect a wide variety of cloven-hoofed domesticated and wild animal species, causing an acute disease characterized by vesicular lesions of the tongue, snout, buccal cavity, feet and teats (Grubman & Baxt, 2004). Despite causing extensive lesions, the cycle of infection in the individual animal is short, and foot-and-mouth disease (FMD) usually resolves without the need for treatment and is seldom lethal in adults (Arzt et al., 2011b). However, the highly contagious nature, wide dissemination and significant economic impact of FMD have made it one of the most feared livestock diseases and a major research focus for more than a century. Progress towards the development of effective tools for FMD control has been hampered by several factors including the cost and logistics of largeanimal experimentation in specialized high-containment facilities, incomplete knowledge of the host's immune systems and lack of immunological reagents compared to biomedical rodent species and humans. These factors delayed the production of vaccines on an industrial scale and this major research goal was subsequently only achieved in the 1950s (Lombard et al., 2007). In a review, Brown (2003) highlighted that this milestone could not have been achieved without certain significant advances in our knowledge of FMD. The first significant advance was the demonstration by Loeffler & Frosch (1897) that the disease was caused by a virus and the second was the establishment of FMD laboratory animal models, including the guinea-pig model (Waldman & Pape, 1920) followed by the suckling mouse model (Skinner, 1951). Although not without their flaws, these FMD laboratory animal models have helped elucidate several mechanisms of FMD pathogenesis, which would have been difficult to achieve directly in target species. These models have provided an accelerated time frame at significantly reduced costs to develop and test vaccine candidates and continue to be a useful tool for interrogating FMDV immune responses. However, we now know that porcine and ru...
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