Vaccine development in horses involves the creation and refinement of immunizations to protect equine populations from infectious diseases. This process includes identifying antigens, formulating vaccines, and evaluating their safety and efficacy through clinical trials. Vaccines stimulate the horse's immune system to recognize and combat specific pathogens, thereby reducing the incidence and severity of diseases. Common equine vaccines target diseases such as equine influenza, tetanus, and West Nile virus. This page compiles peer-reviewed research studies and scholarly articles that explore the methodologies, challenges, and advancements in vaccine development for equine health.
Freitas NFQR, Otaka DY, Galvão CC, de Almeida DM, Ferreira MRA, Moreira Júnior C, Hidalgo MMMH, Conceição FR, Salvarani FM.In horses, Clostridium perfringens is associated with acute and fatal enterocolitis, which is caused by a beta toxin (CPB), and myonecrosis, which is caused by an alpha toxin (CPA). Although the most effective way to prevent these diseases is through vaccination, specific clostridial vaccines for horses against C. perfringens are not widely available. The aim of this study was to pioneer the immunization of horses with three different concentrations (100, 200 and 400 µg) of C. perfringens recombinant alpha (rCPA) and beta (rCPB) proteins, as well as to evaluate the humoral immune response ove...
Hasan SS, Dey D, Singh S, Martin M.Alphaviruses are arboviruses that cause arthritis and encephalitis in humans. Eastern Equine Encephalitis Virus (EEEV) is a mosquito-transmitted alphavirus that is implicated in severe encephalitis in humans with high mortality. However, limited insights are available into the fundamental biology of EEEV and residue-level details of its interactions with host proteins. In recent years, outbreaks of EEEV have been reported mainly in the United States, raising concerns about public safety. This review article summarizes recent advances in the structural biology of EEEV based mainly on single-par...
Santos AC, Nogueira CEW, Dos Santos Suñe Moraes B, Müller V, Mousquer MA, Leite FPL.Equine theileriosis, caused by the Theileria equi protozoan, is a disease of worldwide importance. T. equi expresses surface proteins, of which the EMA-2 protein is a promising antigen for vaccine use. The aim of this study was to evaluate the immune response of adult horses, pregnant mares, and foals to an experimental EMA-2 protein of recombinant T. equi vaccine. A total of 46 horses were used in this study for vaccine trials and challenges. Twelve geldings, 14 pregnant mares, and 14 foals were divided into vaccinated and control groups. Total serum specific anti-rEMA-2 IgG, IgG subclasses, ...
Warda FF, Ahmed HES, Shafik NG, Mikhael CA, Abd-ElAziz HMG, Mohammed WA, Shosha EA.Equine herpesvirus-1 infection in horses causes a wide range of manifestations affecting the respiratory tract. The virus can cause serious economic losses through sporadic abortion in pregnant mares, perinatal death, respiratory disease in young foals. This study was designed to prepare inactivated equine herpesvirus-1 (EHV-1) vaccine using both 0.005 M binary ethylenimine (BEI) and 0.0006% formaldehyde (FA) to decrease the use of BEI and provide a good immunological response. The efficacy, safety, and duration of immunity of the prepared inactivated EHV-1 vaccine were evaluated. Methods: The...
Halpin K, Graham K, Durr PA.Hendra virus (HeV) is a high consequence zoonotic pathogen found in Australia. The HeV vaccine was developed for use in horses and provides a One Health solution to the prevention of human disease. By protecting horses from infection, the vaccine indirectly protects humans as well, as horses are the only known source of infection for humans. The sub-unit-based vaccine, containing recombinant HeV soluble G (sG) glycoprotein, was released by Pfizer Animal Health (now Zoetis) for use in Australia at the end of 2012. The purpose of this study was to collate post-vaccination serum neutralising anti...
Lee H, Yun SH, Hyon JY, Lee SY, Yi YS, Choi CW, Jun S, Park EC, Kim SI.Streptococcus equi subspecies equi is a pathogenic bacterium that causes strangles, a highly contagious respiratory infection in horses and other equines. The limitations of current vaccines against S. equi infection warrants the development of an affordable, safe, and effective vaccine. Because gram-positive extracellular vesicles (EVs) transport various immunogenic antigens, they are attractive vaccine candidates. Here, we purified the EVs of S. equi ATCC 39506 and evaluated them as a vaccine candidate against S. equi infection in mice. As an initial step, comparative proteomic analysis was ...
Barrett RS, Wiethoelter A, Halpin K.To elucidate veterinarians' and horse owners' perceptions towards the use of Hendra virus (HeV) antibody titre testing and how it influences veterinary advice. Methods: Six semi-structured phone interviews were conducted with veterinarians who have submitted samples for HeV antibody titre testing. Interviews were recorded, transcribed and thematically analysed to identify and report common themes within the data. Results: Veterinarians are predominantly using the titre tests as an alternative to vaccination due to clients' fear of vaccine reactions. The high cost of titre testing, the difficul...
Tomlinson JE, Wolfisberg R, Fahnøe U, Patel RS, Trivedi S, Kumar A, Sharma H, Nielsen L, McDonough SP, Bukh J, Tennant BC, Kapoor A, Rosenberg BR....Equine hepacivirus (EqHV) is phylogenetically the closest relative of HCV and shares genome organization, hepatotropism, transient or persistent infection outcome, and the ability to cause hepatitis. Thus, EqHV studies are important to understand equine liver disease and further as an outbred surrogate animal model for HCV pathogenesis and protective immune responses. Here, we aimed to characterize the course of EqHV infection and associated protective immune responses. Seven horses were experimentally inoculated with EqHV, monitored for 6 months, and rechallenged with the same and, subsequen...
Zarski LM, Vaala WE, Barnett DC, Bain FT, Soboll Hussey G.Equine herpesvirus 1 (EHV-1) ubiquitously infects horses worldwide and causes respiratory disease, abortion, and equine herpesvirus myeloencephalopathy. Protection against EHV-1 disease is elusive due to establishment of latency and immune-modulatory features of the virus. These include the modulation of interferons, cytokines, chemokines, antigen presentation, and cellular immunity. Because the modulation of immunity likely occurs at the site of first infection-the respiratory epithelium, we hypothesized that the mucosal influenza vaccine Flu Avert I.N. (Flu Avert), which is known to stimulat...
Chen X, Zhao Y, Su L, Wang L, Ma X, Zhang B, Su Y.Strangles, which is caused by Streptococcus equi subspecies equi, is one of the most prevalent equine infectious diseases and poses heavy economic losses worldwide. Although various vaccines have been used for decades, they seemed to be sub-optimal to demonstrate effective protection, and the antigen component of vaccines against S. equi remains to be optimized. In the present study, three target antigens (M-like protein, α2-macroglobulin and IgG-binding protein, and glyceraldehyde-3-phosphate dehydrogenase) were selected and expressed. Mice were immunized and challenged, and their immune res...
Liu J, Zhang Z, Bai A, Sha Y, Ma L, Qin S, Chen F, Qin S, Wu J.Feline parvovirus (FPV), a type of parvovirus prevalent worldwide, can cause foetal death and acute enteritis in adult cats with severe leukopenia, and yet there are no effective drugs to prevent or treat FPV. Here, the immune effects of two FPV vaccines on horses were compared. IgG was extracted from FPV-immunized horse sera. Equine F(ab') fragments were obtained from pepsin-digested IgG and then purified by protein-G column chromatography. The results showed that the inactivated FPV oil vaccine was more effective than the inactivated FPV propolis vaccine in helping healthy horses to produce ...
Zhang P, Sun Y, Tan C, Ling M, Li X, Wang W, Cong Y.To prevent and control H3N8 subtype equine influenza, we prepared virus-like particles (VLPs) comprising the HA, NA and M1 proteins of H3N8 equine influenza virus (EIV) through the insect cell-baculovirus expression system. The results of Western blot and hemagglutination analyses demonstrated that the constructed VLPs comprising HA, NA and M1 proteins have good hemagglutination activity. Immunoelectron microscope revealed that the VLPs share similar morphology and structure with natural virus particles. The hyperimmune serum from horses immunized with the VLPs were injected into mice by means...
Olguin-Perglione C, Barrandeguy ME.Equine influenza virus (EIV) is one of the most important respiratory pathogens of horses as outbreaks of the disease lead to significant economic losses worldwide. In this review, we summarize the information available on equine influenza (EI) in South America. In the region, the major events of EI occurred almost in the same period in the different countries, and the EIV isolated showed high genetic identity at the hemagglutinin gene level. It is highly likely that the continuous movement of horses, some of them subclinically infected, among South American countries, facilitated the spread o...
León G, Herrera M, Vargas M, Arguedas M, Sánchez A, Segura Á, Gómez A, Solano G, Corrales-Aguilar E, Risner K, Narayanan A, Bailey C, Villalta M....In the current global emergency due to SARS-CoV-2 outbreak, passive immunotherapy emerges as a promising treatment for COVID-19. Among animal-derived products, equine formulations are still the cornerstone therapy for treating envenomations due to animal bites and stings. Therefore, drawing upon decades of experience in manufacturing snake antivenom, we developed and preclinically evaluated two anti-SARS-CoV-2 polyclonal equine formulations as potential alternative therapy for COVID-19. We immunized two groups of horses with either S1 (anti-S1) or a mixture of S1, N, and SEM mosaic (anti-Mix) ...
Sullivan E, Lecollinet S, Kerviel A, Hue E, Pronost S, Beck C, Dumarest M, Zientara S, Roy P.African horse sickness virus (AHSV) is an Orbivirus within the Reoviridae family, spread by Culicoides species of midges, which infects equids with high mortality, particularly in horses and has a considerable impact on the equine industry. In order to control the disease, we previously described Entry Competent Replication Abortive (ECRA) virus strains for each of the nine distinct AHSV serotypes and demonstrated their potential as vaccines, first in type I interferon receptor (IFNAR-/-) knockout mice, and then in ponies. In this report we have investigated whether or not a combination ECRA v...
Onzere CK, Fry LM, Bishop RP, Silva MG, Bastos RG, Knowles DP, Suarez CE.Theileria equi is a widely distributed apicomplexan parasite that causes severe hemolytic anemia in equid species. There is currently no effective vaccine for control of the parasite and understanding the mechanism that T. equi utilizes to invade host cells may be crucial for vaccine development. Unlike most apicomplexan species studied to date, the role of micronemes in T. equi invasion of host cells is unknown. We therefore assessed the role of the T. equi claudin-like apicomplexan microneme protein (CLAMP) in the invasion of equine erythrocytes as a first step towards understanding the role...
Redmond EF, Jones D, Rushton J.African horse sickness (AHS) is endemic in sub-Saharan Africa posing a threat to equine populations in non-endemic regions. Available vaccine technologies have limitations, creating barriers to horse movement, AHS control and, in non-endemic areas or countries, rapid elimination of virus after incursion. The literature lacks an economic assessment of the benefits of bringing a new, more effective AHS vaccine to market. Objective: The study assesses the economic impact of AHS and tests the hypothesis that investment in a safer, more effective AHS vaccine would give an economic return. Methods: ...
Urban JF, Nielsen MK, Gazzola D, Xie Y, Beshah E, Hu Y, Li H, Rus F, Flanagan K, Draper A, Vakalapudi S, Li RW, Ostroff GR, Aroian RV. and are important parasites in the family Ascarididae, large, ubiquitous intestinal-dwelling nematodes infecting all classes of vertebrates. Parasitic nematode drug resistance in veterinary medicine and drug recalcitrance in human medicine are increasing worldwide, with few if any new therapeutic classes on the horizon. Some of these parasites are zoonotic, , is passed from humans to pigs and . The development of new therapies against this family of parasites would have major implications for both human and livestock health. Here we tested the therapeutic ability of a paraprobiotic or dead ...
Yuen KY, Bielefeldt-Ohmann H.Ross River virus (RRV) has recently been suggested to be a potential emerging infectious disease worldwide. RRV infection remains the most common human arboviral disease in Australia, with a yearly estimated economic cost of $4.3 billion. Infection in humans and horses can cause chronic, long-term debilitating arthritogenic illnesses. However, current knowledge of immunopathogenesis remains to be elucidated and is mainly inferred from a murine model that only partially resembles clinical signs and pathology in human and horses. The epidemiology of RRV transmission is complex and multifactorial...
Karam B, Wilson WD, Chambers TM, Reedy S, Pusterla N.The use of a hemagglutination inhibition (HI) assay to assess humoral immune response to equine influenza virus (EIV) vaccines from various manufacturers administered to previously immunized adult horses was investigated. Subjects were allocated into one of 3 groups and vaccinated with various commercially available vaccines. Groups were subdivided into subjects that received 1 dose of a particular vaccine and those that received a second dose, 30 d later. Serum was collected at various times to assess antibody responses to contemporary EIV Florida sub-lineage strains. Statistical significance...
Laval K, Poelaert KCK, Van Cleemput J, Zhao J, Vandekerckhove AP, Gryspeerdt AC, Garré B, van der Meulen K, Baghi HB, Dubale HN, Zarak I....Equine herpesvirus type 1 (EHV-1) is an alphaherpesvirus related to pseudorabies virus (PRV) and varicella-zoster virus (VZV). This virus is one of the major pathogens affecting horses worldwide. EHV-1 is responsible for respiratory disorders, abortion, neonatal foal death and equine herpes myeloencephalopathy (EHM). Over the last decade, EHV-1 has received growing attention due to the frequent outbreaks of abortions and/or EHM causing serious economical losses to the horse industry worldwide. To date, there are no effective antiviral drugs and current vaccines do not provide full protection a...
Ohta M, Bannai H, Kambayashi Y, Tamura N, Tsujimura K, Yamayoshi S, Kawaoka Y, Nemoto M.Keeping vaccine strains up to date is the key to controlling equine influenza (EI). Viruses generated by reverse genetics (RG) are likely to be effective for quickly updating a vaccine strain. Objective: To evaluate the growth properties of an RG virus in embryonated chicken eggs, and to evaluate antibody responses to a formalin-inactivated vaccine derived from the RG virus in Thoroughbred horses. Methods: In vitro and in vivo experiments. Methods: Wild-type (WT) viruses (A/equine/Ibaraki/1/2007) or RG viruses (consisting of haemagglutinin [HA] and neuraminidase genes derived from A/equine/Iba...
Bannai H, Tominari M, Kambayashi Y, Nemoto M, Tsujimura K, Ohta M.Antibody response in horses after accelerated-schedule Getah virus vaccination was evaluated for its potential adoption during outbreaks. One-year-old Thoroughbred horses received two doses of priming vaccinations following an accelerated schedule (accelerated group: 14-day interval, n = 30) or the conventional schedule (control group: 28-day interval, n = 30). At Day 14, both groups showed similar seropositive rates (66.7% in control group and 73.3% in accelerated group) and geometric mean (GM) virus-neutralizing titers (5.2 [95% confidence interval (CI), 3.0-8.8] in control group and 5.3...
Zhang H, Zhou T, Su L, Wang H, Zhang B, Su Y.Strangles, which is caused by Streptococcus equi subspecies equi (S. equi), is one of the most prevalent equine infectious diseases with worldwide distribution and leads to serious economic loss in the horse industry. Sortase A (srtA) is a transpeptidase that anchors multiple virulence-associated surface proteins to the cell surface of S. equi. srtA plays a major role in S. equi infection and colonization of the host cell. In this study, we aimed to investigate the effects of srtA mutation on the phagocytic activity and immunogenicity of S. equi. The point-mutated recombinant sortases, includi...
Legere RM, Cohen ND, Poveda C, Bray JM, Barhoumi R, Szule JA, de la Concha-Bermejillo A, Bordin AI, Pollet J.Vaccines and therapeutics using in vitro transcribed mRNA hold enormous potential for human and veterinary medicine. Transfection agents are widely considered to be necessary to protect mRNA and enhance transfection, but they add expense and raise concerns regarding quality control and safety. We found that such complex mRNA delivery systems can be avoided when transfecting epithelial cells by aerosolizing the mRNA into micron-sized droplets. In an equine in vivo model, we demonstrated that the translation of mRNA into a functional protein did not depend on the addition of a polyethylenimine (...
Fearon SH, Dennis SJ, Hitzeroth II, Rybicki EP, Meyers AE.African horse sickness (AHS) is a devastating viral disease affecting equines and has resulted in many disastrous epizootics. To date, no successful therapeutic treatment exists for AHS, and commercially used live-attenuated vaccines have various undesirable side effects. Previous studies have shown that mice inoculated with insoluble African horse sickness virus (AHSV) VP7 crystals are protected from live challenge with a lethal dose of AHSV. This study investigates the humoral and cell-mediated immune responses in guinea-pigs to a safer monovalent vaccine alternative based on AHSV-5 VP7 quas...
Yuen KY, Fraser NS, Henning J, Halpin K, Gibson JS, Betzien L, Stewart AJ.Hendra virus (HeV) continues to pose a serious public health concern as spillover events occur sporadically. Terminally ill horses can exhibit a range of clinical signs including frothy nasal discharge, ataxia or forebrain signs. Early signs, if detected, can include depression, inappetence, colic or mild respiratory signs. All unvaccinated ill horses in areas where flying foxes exist, may potentially be infected with HeV, posing a significant risk to the veterinary community. Equivac® HeV vaccine has been fully registered in Australia since 2015 (and under an Australian Pesticides and Veteri...
Reemers S, van Bommel S, Cao Q, Sutton D, van de Zande S.Equine influenza virus (EIV) is a major cause of respiratory disease in horses. Vaccination is an effective tool for infection control. Although various EIV vaccines are widely available, major outbreaks occurred in Europe in 2018 involving a new EIV H3N8 FC1 strain. In France, it was reported that both unvaccinated and vaccinated horses were affected despite >80% vaccination coverage and most horses being vaccinated with a vaccine expressing FC1 antigen. This study assessed whether vaccine type, next to antigenic difference between vaccine and field strain, plays a role. Horses were vaccin...
Saiz JC.West Nile virus (WNV) is a widely distributed enveloped flavivirus transmitted by mosquitoes, which main hosts are birds. The virus sporadically infects equids and humans with serious economic and health consequences, as infected individuals can develop a severe neuroinvasive disease that can even lead to death. Nowadays, no WNV-specific therapy is available and vaccines are only licensed for use in horses but not for humans. While several methodologies for WNV vaccine development have been successfully applied and have contributed to significantly reducing its incidence in horses in the US, n...
Zilch TJ, Lee JJ, Bressan GC, McDonough SP, Mohammed HO, Divers TJ, Chang YF.The current gold standard diagnostic test for leptospirosis is the microscopic agglutination test (MAT), which has many drawbacks; therefore, the development of a better and easier serological test for leptospirosis is needed. Objective: To apply reverse vaccinology (RV) and antigenic selection on the assortment of leptospiral targets and evaluate their potential for use as reagents for the diagnosis of equine leptospirosis. Methods: Cross-sectional study. Methods: The antigenic selection parameters were: proteins with antigenicity score ≥0.5 (VaxiJen), at least one B cell epitope and size b...
Anniballi F, Fiore A, Löfström C, Skarin H, Auricchio B, Woudstra C, Bano L, Segerman B, Koene M, Båverud V, Hansen T, Fach P, Tevell Aberg A....Botulism is a severe neuroparalytic disease that affects humans, all warm-blooded animals, and some fishes. The disease is caused by exposure to toxins produced by Clostridium botulinum and other botulinum toxin-producing clostridia. Botulism in animals represents a severe environmental and economic concern because of its high mortality rate. Moreover, meat or other products from affected animals entering the food chain may result in a public health problem. To this end, early diagnosis is crucial to define and apply appropriate veterinary public health measures. Clinical diagnosis is based on...
Eaton BT, Broder CC, Wang LF.Within the past decade a number of new zoonotic paramyxoviruses emerged from flying foxes to cause serious disease outbreaks in man and livestock. Hendra virus was the cause of fatal infections of horses and man in Australia in 1994, 1999 and 2004. Nipah virus caused encephalitis in humans both in Malaysia in 1998/99, following silent spread of the virus in the pig population, and in Bangladesh from 2001 to 2004 probably as a result of direct bat to human transmission and spread within the human population. Hendra and Nipah viruses are highly pathogenic in humans with case fatality rates of 40...
Gershwin LJ.Vaccines are important for providing protection from infectious diseases. Vaccination initiates a process that stimulates development of a robust and long-lived immune response to the disease agents in the vaccine. Side effects are sometimes associated with vaccination. These vary from development of acute hypersensitivity responses to vaccine components to local tissue reactions that are annoying but not significantly detrimental to the patient. The pathogenesis of these responses and the consequent clinical outcomes are discussed. Overstimulation of the immune response and the potential rela...
Laval K, Poelaert KCK, Van Cleemput J, Zhao J, Vandekerckhove AP, Gryspeerdt AC, Garré B, van der Meulen K, Baghi HB, Dubale HN, Zarak I....Equine herpesvirus type 1 (EHV-1) is an alphaherpesvirus related to pseudorabies virus (PRV) and varicella-zoster virus (VZV). This virus is one of the major pathogens affecting horses worldwide. EHV-1 is responsible for respiratory disorders, abortion, neonatal foal death and equine herpes myeloencephalopathy (EHM). Over the last decade, EHV-1 has received growing attention due to the frequent outbreaks of abortions and/or EHM causing serious economical losses to the horse industry worldwide. To date, there are no effective antiviral drugs and current vaccines do not provide full protection a...
Khusro A, Aarti C, Rivas-Caceres RR, Barbabosa-Pliego A.Equine herpesvirus-1 (EHV-1) is one of the most common and ubiquitous viral pathogens infecting equines, particularly horses worldwide. The EHV-1 is known to induce not only humoral but also cellular immune responses in horses. Respiratory distress, abortion in pregnant mares, neurological disorders, and neonatal foal deaths represent EHV-1 infection. Despite the limited success of inactivated, subunit, live, and DNA vaccines, over the past few decades, vaccination remains the prime preventive option to combat EHV-1 infection in horses. However, current vaccines lack the potentiality to protec...
Townsend HG, Penner SJ, Watts TC, Cook A, Bogdan J, Haines DM, Griffin S, Chambers T, Holland RE, Whitaker-Dowling P, Youngner JS, Sebring RW.A randomised, controlled, double-blind, influenza virus, aerosol challenge of horses was undertaken to determine the efficacy of a cold-adapted, temperature sensitive, modified-live virus, intranasal, equine influenza vaccine. Ninety 11-month-old influenza-naïve foals were assigned randomly to 3 groups (20 vaccinates and 10 controls per group) and challenged 5 weeks, 6 and 12 months after a single vaccination. Challenges were performed on Day 0 in a plastic-lined chamber. Between Days 1 and 10, animals were examined daily for evidence of clinical signs of influenza. Nasal swabs for virus isol...
Martella V, Elia G, Decaro N, Di Trani L, Lorusso E, Campolo M, Desario C, Parisi A, Cavaliere N, Buonavoglia C.In December 2005, equine influenza virus infection was confirmed as the cause of clinical respiratory disease in vaccinated horses in Apulia, Italy. The infected horses had been vaccinated with a vaccine that contained strains representatives from both the European (A/eq/Suffolk/89) and American (A/eq/Newmarket/1/93) H3N8 influenza virus lineages, and the H7N7 strain A/eq/Praga/56. Genetic characterization of the hemagglutinin (HA) and neuraminidase (NA) genes of the virus from the outbreak, indicated that the isolate (A/eq/Bari/2005) was an H3N8 strain closely related to recent representative...
Nishimoto KP, Laust AK, Wang K, Kamrud KI, Hubby B, Smith JF, Nelson EL.Dendritic cells (DCs) consist of heterogeneous phenotypic populations and have diverse immunostimulatory functions dependent on both lineage and functional phenotype, but as exceptionally potent antigen-presenting cells, they are targets for generating effective antigen-specific immune responses. A promising replicon particle vector derived from Venezuelan equine encephalitis virus (VEE) has been reported to transduce murine footpad DCs. However, the receptive DC subset, the degree of restriction for this tropism, and the extent of conservation between rodents and humans have not been well cha...
Gildea S, Quinlivan M, Arkins S, Cullinane A.Antigenic and genetic drift of equine influenza (EI) virus is monitored annually by the Expert Surveillance Panel (ESP), which make recommendations on the need to update vaccines. Surveillance programmes are essential for this process to operate effectively and to decrease the risk of disease spread through the international movement of subclinically infected vaccinated horses. Not only is surveillance necessary to inform vaccine companies which strains are in circulation, but it serves as an early warning system for horse owners, trainers and veterinary clinicians, facilitating the implementa...
Mumford JA, Wood J.Shortcomings in the original methods (based on haemagglutination of erythrocytes) used to measure potency of equine influenza vaccines and antibody responses stimulated by vaccines, coupled with the lack of a reliable challenge system in the target species, has hindered progress in identifying the antigenic content required to provide protection. Reliable methods are now available for measuring the haemagglutinin (HA) content of vaccines and the antibody responses they elicit. The development of challenge systems in the target species has allowed antibody levels consistent with protection to b...
Nelson KM, Schram BR, McGregor MW, Sheoran AS, Olsen CW, Lunn DP.Inactivated alum-adjuvanted conventional equine influenza virus vaccines are of poor efficacy and offer limited short-term protection against infection. In sharp contrast, natural infection with equine influenza virus confers long-term protective immunity. In order to identify the protective immune responses to equine influenza virus, the influenza virus-specific IgA, IgGa, IgGb, IgGc and IgG(T) antibody responses in nasal secretions and serum induced by natural infection and a commercial vaccine were studied by ELISA. Two groups of four influenza-naive ponies were established. In the natural ...
Alves Beuttemmüller E, Woodward A, Rash A, Dos Santos Ferraz LE, Fernandes Alfieri A, Alfieri AA, Elton D.An extensive outbreak of equine influenza occurred across multiple countries in South America during 2012. The epidemic was first reported in Chile then spread to Brazil, Uruguay and Argentina, where both vaccinated and unvaccinated animals were affected. In Brazil, infections were widespread within 3months of the first reported cases. Affected horses included animals vaccinated with outdated vaccine antigens, but also with the OIE-recommended Florida clade 1 strain South Africa/4/03. Methods: Equine influenza virus strains from infected horses were isolated in eggs, then a representative stra...
Baz M, Paskel M, Matsuoka Y, Zengel J, Cheng X, Jin H, Subbarao K.Since it is difficult to predict which influenza virus subtype will cause an influenza pandemic, it is important to prepare influenza virus vaccines against different subtypes and evaluate the safety and immunogenicity of candidate vaccines in preclinical and clinical studies prior to a pandemic. In addition to infecting humans, H3 influenza viruses commonly infect pigs, horses, and avian species. We selected 11 swine, equine, and avian H3 influenza viruses and evaluated their kinetics of replication and ability to induce a broadly cross-reactive antibody response in mice and ferrets. The swin...
Dennis SJ, Meyers AE, Guthrie AJ, Hitzeroth II, Rybicki EP.African horse sickness (AHS) is a debilitating and often fatal viral disease affecting horses in much of Africa, caused by the dsRNA orbivirus African horse sickness virus (AHSV). Vaccination remains the single most effective weapon in combatting AHS, as there is no treatment for the disease apart from good animal husbandry. However, the only commercially available vaccine is a live-attenuated version of the virus (LAV). The threat of outbreaks of the disease outside its endemic region and the fact that the LAV is not licensed for use elsewhere in the world, have spurred attempts to develop an...
Daly JM, Yates PJ, Newton JR, Park A, Henley W, Wood JL, Davis-Poynter N, Mumford JA.Two lineages of antigenically distinct equine influenza A H3N8 subtype viruses, American and European, co-circulate. Experiments were conducted in ponies to investigate the protection induced by vaccines containing virus from one lineage against challenge infection with homologous or heterologous virus. Regression analysis showed that vaccinated ponies with average pre-challenge single radial haemolysis (SRH) antibody levels (i.e. 45-190mm2) had a higher probability of becoming infected if they were vaccinated with virus heterologous to the challenge strain than if they were vaccinated with ho...
Chirnside ED, de Vries AA, Mumford JA, Rottier PJ.Complementary DNAs encoding ORFs 2 to 7 equine arteritis virus (EAV) have been cloned into the expression vector pGEX to produce glutathione-S-transferase fusion proteins. Recombinant proteins were affinity purified and screened in ELISA with equine sera to identify immunoreactive polypeptides. The large envelope glycoprotein (GL) was identified as the most reactive to EAV-positive equine sera and an immuno-dominant epitope was mapped between amino acids 55 and 98 by subcloning and expression. A fusion protein covering this region and a GL-specific synthetic peptide (residues 75 through 97) in...
Saiz JC.West Nile virus (WNV) is a widely distributed enveloped flavivirus transmitted by mosquitoes, which main hosts are birds. The virus sporadically infects equids and humans with serious economic and health consequences, as infected individuals can develop a severe neuroinvasive disease that can even lead to death. Nowadays, no WNV-specific therapy is available and vaccines are only licensed for use in horses but not for humans. While several methodologies for WNV vaccine development have been successfully applied and have contributed to significantly reducing its incidence in horses in the US, n...
Paillot R, Kydd JH, Sindle T, Hannant D, Edlund Toulemonde C, Audonnet JC, Minke JM, Daly JM.In horses, equine influenza virus (EIV) is a leading cause of respiratory disease. Conventional inactivated vaccines induce a short-lived immune response. By comparison, natural infection confers a long-term immunity to re-infection. An aim of new equine influenza vaccines is to more closely mimic natural infection in order to achieve a better quality of immunity. A new live recombinant vaccine derived from the canarypox virus vector and expressing haemagglutinin genes of EIV (subtype H3N8) has been developed. Stimulation of the immune system was studied after immunisation with this canarypox-...
Raabe ML, Issel CJ, Cook SJ, Cook RF, Woodson B, Montelaro RC.We have previously reported that immunization of ponies with a baculovirus-expressed recombinant surface unit envelope protein (rgp90) for equine infectious anemia virus (EIAV) resulted in enhancement of disease symptoms and virus replication in 4 of 4 vaccine recipients subjected to a heterologous virus challenge (rpg90 I vaccine trial) (Wang et al., 1994). To extend these studies of EIAV vaccine enhancement, two additional and independent rgp90 vaccine trials (rgp90 II and rgp90 III) were performed. Combined, a total of 13 ponies were immunized with the rgp90 immunogen using our standard vac...
Kanai Y, van Rijn PA, Maris-Veldhuis M, Kaname Y, Athmaram TN, Roy P.African horse sickness (AHS) is an equine disease with a mortality of up to 90% for susceptible horses. The causative agent AHS virus (AHSV) is transmitted by species of Culicoides. AHSV serogroup within the genus Orbivirus of the Reoviridae family consists of nine serotypes that show no or very limited cross-neutralization. Of the seven structural proteins (VP1-VP7) of AHSV, VP2 is the serotype specific protein, and the major target for neutralizing antibodies. In this report, recombinant VP2 proteins of all nine serotypes were expressed individually by the baculovirus expression system and t...
Olomski F, Fettelschoss V, Jonsdottir S, Birkmann K, Thoms F, Marti E, Bachmann MF, Kündig TM, Fettelschoss-Gabriel A.Insect bite hypersensitivity (IBH) is the most common seasonal pruritic allergic dermatitis of horses occurring upon insect bites. In recent years, a major role for IL-31 in allergic pruritus of humans, monkeys, dogs, and mice was acknowledged. Here, we investigate the role of IL-31 in IBH of horses and developed a therapeutic vaccine against equine IL-31 (eIL-31). IL-31 levels were quantified in allergen-stimulated peripheral blood mononuclear cells (PBMCs) and skin punch biopsies of IBH lesions and healthy skin from IBH-affected and healthy horses. The vaccine consisted of eIL-31 covalently ...
Mendoza L, Mandy W, Glass R.The immunotherapeutic properties of a new Pythium insidiosum-vaccine formulation (PIV), was evaluated in 18 horses and 6 dogs with proven pythiosis from different enzootic areas in the United States. All injected horses but one responded with a weak (=29 mm, n=3), a mild (30-90 mm, n=7) or a strong (=100 mm, n=7) inflammatory reactions at the site of injection. Three equines with weak or negative reactions at the injection site were not cured. Seven equines with strong reactions at their injection sites, however, were cured. Six of the eight horses with mild reactions were also cured. The rema...
van de Water SG, van Gennip RG, Potgieter CA, Wright IM, van Rijn PA.African horse sickness virus (AHSV) is a virus species in the genus Orbivirus of the family Reoviridae. There are nine serotypes of AHSV showing different levels of cross neutralization. AHSV is transmitted by species of Culicoides biting midges and causes African horse sickness (AHS) in equids, with a mortality rate of up to 95% in naive horses. AHS has become a serious threat for countries outside Africa, since endemic Culicoides species in moderate climates appear to be competent vectors for the related bluetongue virus (BTV). To control AHS, live-attenuated vaccines (LAVs) are used in Afri...
Diouf ND, Etter E, Lo MM, Lo M, Akakpo AJ.Since first being detected in Nigeria in January 2007, African horse sickness virus serotype 2 (AHSV-2) has spread throughout the northern hemisphere, and was first reported in Senegal. A retrospective study was conducted from December 2009 to April 2010 using data collected in the field combined with information available at the Direction of Veterinary Services. The epidemic started in the Dakar region with two outbreaks in March and June 2007, respectively, and spread in several parts of the country between July and November 2007. During this period, 232 outbreaks and 1137 horse deaths were ...
Craigo JK, Montelaro RC.Equine infectious anemia (EIA), identified in 1843 [1] as an infectious disease of horses and as a viral infection in 1904, remains a concern in veterinary medicine today. Equine infectious anemia virus (EIAV) has served as an animal model of HIV-1/AIDS research since the original identification of HIV. Similar to other lentiviruses, EIAV has a high propensity for genomic sequence and antigenic variation, principally in its envelope (Env) proteins. However, EIAV possesses a unique and dynamic disease presentation that has facilitated comprehensive analyses of the interactions between the evolv...
Tagmyer TL, Craigo JK, Cook SJ, Even DL, Issel CJ, Montelaro RC.A highly effective attenuated equine infectious anemia virus (EIAV) vaccine (EIAV(D9)) capable of protecting 100% of horses from disease induced by a homologous Env challenge strain (EIAV(PV)) was recently tested in ponies to determine the level of protection against divergent Env challenge strains (J. K. Craigo, B. S. Zhang, S. Barnes, T. L. Tagmyer, S. J. Cook, C. J. Issel, and R. C. Montelaro, Proc. Natl. Acad. Sci. USA 104:15105-15110, 2007). An inverse correlation between challenge strain Env variation and vaccine protection from disease was observed. Given the striking differences in pro...
Hammond SA, Raabe ML, Issel CJ, Montelaro RC.We previously demonstrated in trials of a variety of experimental vaccines to equine infectious anemia virus (EIAV) a remarkable spectrum of efficacy ranging from sterilizing protection to severe enhancement of virus replication and disease, depending on the immunization strategy used. This range of vaccine efficacy observed in vivo offers a unique opportunity for evaluating potential in vitro immune correlates of protection and enhancement. We describe here a comprehensive analysis and comparison of EIAV envelope-specific antibody responses elicited by attenuated, inactivated whole virus and ...
Rossi SL, Guerbois M, Gorchakov R, Plante KS, Forrester NL, Weaver SC.Venezuelan equine encephalitis virus (VEEV) is an arbovirus that causes periodic outbreaks that impact equine and human populations in the Americas. One of the VEEV subtypes located in Mexico and Central America (IE) has recently been recognized as an important cause of equine disease and death, and human exposure also appears to be widespread. Here, we describe the use of an Internal Ribosome Entry Site (IRES) from encephalomyocarditis virus to stably attenuate VEEV, creating a vaccine candidate independent of unstable point mutations. Mice infected with this virus produced antibodies and wer...
Ghosh M, Sharma N, Singh AK, Gera M, Pulicherla KK, Jeong DK.For more than a quarter of a century, sequencing technologies from Sanger's method to next-generation high-throughput techniques have provided fascinating opportunities in the life sciences. The continuing upward trajectory of sequencing technologies will improve livestock research and expedite the development of various new genomic and technological studies with farm animals. The use of high-throughput technologies in livestock research has increased interest in metagenomics, epigenetics, genome-wide association studies, and identification of single nucleotide polymorphisms and copy number va...
Cauchard S, Bermúdez-Humarán LG, Blugeon S, Laugier C, Langella P, Cauchard J.Rhodococcus equi causes severe pneumonia in foals and has recently gained attention as a significant opportunistic pathogen in immunocompromised humans. However, no effective vaccine to prevent rhodococcosis is currently available. In this study, we have engineered the food-grade bacterium Lactococcus lactis to secrete the virulence-associated protein A from R. equi (LL-VapA). The immunogenic potential of LL-VapA strain was then evaluated after either intragastric or intranasal immunization in mice either alone or in combination with LL-Lep, a recombinant strain of L. lactis secreting biologic...
