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Epizootic haemorrhagic disease (EHD), caused by the EHD virus (EHDV), is a vector-borne viral disease transmitted through Culicoides biting midges. EHDV comprises seven serotypes (1, 2, and 4-8), with EHDV-8 having recently emerged and spread in Europe over the last two years. Such event has raised concerns about the significant threat posed by EHDV-8 to livestock industry. In this study, an inactivated vaccine against EHDV-8 (vEHDV8-IZSAM) was developed. Safety and efficacy of the vaccine were evaluated in calves through clinical, serological, and virological monitoring following experimental challenge. The vaccine was proven safe, with only transient fever and localized reactions observed in a few animals, consistent with adjuvanted vaccine side effects. vEHDV8-IZSAM elicited a robust humoral response, as evidenced by the presence of neutralizing antibodies. After challenge with a virulent isolate, viraemia and clinical signs were evidenced in control animals but in none of the vaccinated animals. This study highlights the potential of vEHDV8-IZSAM as a safe and highly effective vaccine against EHDV-8 in cattle. It offers protection from clinical disease and effectively prevents viraemia. With the recent spread of EHDV-8 in European livestock, the use of an inactivated vaccine could be key in protecting animals from clinical disease and thus to mitigate the economic impact of the disease. Further investigations are warranted to assess the duration of the induced immunity and the applicability of this vaccine in real-world settings. Accordingly, joint efforts between public veterinary institutions and pharmaceutical companies are recommended to scale up vaccine production., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Mention of trade names or commercial products in this article is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the IZSAM., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Most viral diseases display a variable clinical outcome due to differences in virus strain virulence and/or individual host susceptibility to infection. Understanding the biological mechanisms differentiating a viral infection displaying severe clinical manifestations from its milder forms can provide the intellectual framework toward therapies and early prognostic markers. This is especially true in arbovirus infections, where most clinical cases are present as mild febrile illness. Here, we used a naturally occurring vector-borne viral disease of ruminants, bluetongue, as an experimental system to uncover the fundamental mechanisms of virus-host interactions resulting in distinct clinical outcomes. As with most viral diseases, clinical symptoms in bluetongue can vary dramatically. We reproduced experimentally distinct clinical forms of bluetongue infection in sheep using three bluetongue virus (BTV) strains (BTV-1IT2006, BTV-1IT2013 and BTV-8FRA2017). Infected animals displayed clinical signs varying from clinically unapparent, to mild and severe disease. We collected and integrated clinical, haematological, virological, and histopathological data resulting in the analyses of 332 individual parameters from each infected and uninfected control animal. We subsequently used machine learning to select the key viral and host processes associated with disease pathogenesis. We identified and experimentally validated five different fundamental processes affecting the severity of bluetongue: (i) virus load and replication in target organs, (ii) modulation of the host type-I IFN response, (iii) pro-inflammatory responses, (iv) vascular damage, and (v) immunosuppression. Overall, we showed that an agnostic machine learning approach can be used to prioritise the different pathogenetic mechanisms affecting the disease outcome of an arbovirus infection., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Herder et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Lumpy skin disease (LSD) is a viral disease of cattle and water buffalo characterized by cutaneous nodules, biphasic fever, and lymphadenitis. LSD is endemic in Africa and the Middle East but has spread to different Asian countries in recent years. The disease is well characterized in cattle while little is known about the disease in buffaloes in which no experimental studies have been conducted. Six buffaloes and two cattle were inoculated with an Albanian LSD virus (LSDV) field strain and clinically monitored for 42 days. Only two buffaloes showed fever, skin nodules, and lymphadenitis. All samples collected (blood, swabs, biopsies, and organs) were tested in real-time PCR and were negative. Between day 39 and day 42 after inoculation, anti-LSDV antibodies were detected in three buffaloes by ELISA, but all sera were negative by virus neutralization test (VNT). Cattle showed severe clinical signs, viremia, virus shedding proven by positive real-time PCR results, and seroconversion confirmed by both ELISA and VNT. Clinical findings suggest that susceptibility in buffaloes is limited compared to in cattle once experimentally infected with LSDV. Virological results support the hypothesis of buffalo resistance to LSD and its role as an accidental non-adapted host. This study highlights that the sensitivity of ELISA and VNT may differ between animal species and further studies are needed to investigate the epidemiological role of water buffalo.

The significance of Trypanosoma equiperdum as the causative agent of dourine cannot be understated, especially given its high mortality rate among equids. International movement of equids should be subject to thorough health checks and screenings to ensure that animals are not infected with Trypanosoma equiperdum . This involves the implementation of quarantine protocols, testing procedures, and the issuance of health certificates to certify the health status of the animals. Three proteins, the peptidyl-prolyl cis-trans isomerase (A0A1G4I8N3), the GrpE protein homolog (A0A1G4I464) and the transport protein particle (TRAPP) component, putative (A0A1G4I740) (UniProt accession numbers SCU68469.1, SCU66661.1 and SCU67727.1), were identified as unique to T. equiperdum by bioinformatics analysis. The proteins were expressed as recombinant proteins and tested using an indirect ELISA and immunoblotting test with a panel of horse positive and negative sera for dourine. The diagnostic sensitivity, specificity and accuracy of the i-ELISAs were 86.7%, 53.8% and 59.0% for A0A1G4I8N3; 53.3%, 58.7% and 57.9% for A0A1G4I464; and 73.3%, 65.0% and 66.3% for A0A1G4I740, respectively, while the diagnostic sensitivity, specificity and accuracy of immunoblotting were 86.7%, 92.5% and 91.6% for A0A1G4I8N3; 46.7%, 81.3% and 75.8% for A0A1G4I464; and 80.0%, 63.8% and 66.3% for A0A1G4I740. Among the three proteins evaluated in the present work, A0A1G4I8N3 provided the best results when tested by immunoblotting; diagnostic application of this protein should be further investigated using a greater number of positive and negative sera.