Vaccination in horses involves the administration of antigenic material to stimulate an immune response, providing protection against specific infectious diseases. This process is a key component of preventive equine healthcare, aiming to reduce the incidence and severity of illnesses such as equine influenza, tetanus, and West Nile virus. Vaccines can be administered via various routes and may contain live attenuated, inactivated, or subunit components. The immune response elicited by vaccination helps in the development of immunological memory, enabling horses to respond more effectively upon exposure to the actual pathogen. This page compiles peer-reviewed research studies and scholarly articles that explore the development, efficacy, and safety of vaccines in equine populations.
Hassanain MM, al-Afaleq AI, Soliman IM, Abdullah SK.Two 7-year old Arabian racing horses were reported to show typical AHS symptoms in Qatar and died shortly after. The horses had been vaccinated with formol inactivated vaccine approximately 10 days before the onset of the disease. Blood samples from these horses were collected and AHS virus isolated from one sample after intracerebral (i.c.) inoculation into suckling mice. The virus identity was confirmed by complement fixation test (CFT) using the virus antigen and reference type 9 of AHS virus hyperimmune serum. The serotype of the isolated virus was identified by serum neutralization test (...
Cook RF, Gann SJ, Mumford JA.An enzyme-linked immunosorbent assay (ELISA) was developed for the detection of serum antibodies to equine arteritis virus (EAV). Results from this assay produced a good correlation with results from virus neutralisation tests in horses which had not been regularly vaccinated with commercially available mammalian tissue culture-derived viral vaccines. Vaccination of some horses with tissue culture-derived vaccines induced the formation of antibodies to bovine serum. These antibodies reacted with the bovine protein contaminants in the EAV ELISA antigen, producing false-positive results. Non-vir...
Kinney RM, Johnson BJ, Welch JB, Tsuchiya KR, Trent DW.Nucleotide sequence analysis of cDNA clones covering the entire genomes of Trinidad donkey (TRD) Venezuelan equine encephalitis (VEE) virus and its vaccine derivative, TC-83, has revealed 11 differences between the genomes of TC-83 virus and its parent. One nucleotide substitution and a single nucleotide deletion occurred in the 5'- and 3'-noncoding regions of the TC-83 genome, respectively. The deduced amino acid sequences of the nonstructural polypeptides of the two viruses differed only in a conservative Ser(TRD) to Thr(TC-83) substitution in nonstructural protein (nsP) three at amino acid ...
Meyer H, Hübert PH.The production and differentiation of monoclonal antibodies (mabs) against the Rac-H strain of EHV-1 used as an attenuated live vaccine to prevent rhinopneumonitis and abortion is described. Seven different antigenic sites were detected by the 15 mabs produced. EHV-1 specific mabs as well as EHV-1 and -4 common mabs could be established, allowing easy typing of EHV isolates. One mab recognized the vaccine strain only. This reaction was used to investigate a possible involvement of the vaccine strain in cases of abortion. Common antigenic determinants with EHV-1,-3,-4 and BHV-1 could also be de...
Stokes A, Wardley RC.Immunity to equine herpesvirus type 1 (EHV-1) was evaluated using sera collected from yearling horses involved in a trial of a commercial vaccine. Measurement of the ability of these sera to mediate antibody-dependent cellular cytotoxicity and complement-dependent lysis revealed that these mechanisms, although potentially important in recovery from EHV-1 infection, do not play a role in protection following vaccination.
Thomas RJ, Rosenthal DV, Rogers RJ.A toxoid was prepared from type B toxin of Clostridium botulinum by treatment with 0.6% formalin for 6 weeks. The toxoid was adsorbed to aluminium hydroxide and this vaccine was evaluated for safety in guinea pigs, mice and horses, and for immunogenicity in guinea pigs and horses. Neutralising antitoxin was demonstrated in adult horses receiving two 2 ml subcutaneous doses 6 weeks apart, and in a foal which suckled its vaccinated dam. Another vaccinated mare and the passively immunised foal were protected against subcutaneous injection of 1600 and 2000 mouse lethal doses of toxin per kg respec...
Gearhart MA, Webb PA, Knight AP, Salman MD, Smith JA, Erickson GA.Two doses of a formalin-killed, cell culture-derived vesicular stomatitis virus (vsv)-New Jersey serotype vaccine were administered intramuscularly, 30 days apart, to all lactating and nonlactating cows in a 350-cow dairy herd. Serum specimens were obtained serially from 96 cows before vaccination and at 30, 52 and 80 days after vaccination and from 24 of these cows 175 days after vaccination. Serum neutralizing antibody titers to vsv-New Jersey serotype were determined from serum-dilution, plaque-reduction tests. Serum neutralizing antibody titers also were determined during the same period f...
Woolcock JB, Mutimer MD, Bowles PM.Normal horses of all ages regularly show evidence of having responded immunologically to R. equi, thus adding serological support to epidemiological evidence that this organism is a normal intestinal inhabitant. More animals from "diseased" farms show a stronger antibody response when compared with foals from "healthy" farms. Various serological tests have been used to detect evidence of infection and to relate antibody level to severity of disease. Anti-R. equi IgG antibody levels, as measured by ELISA, are raised significantly during natural infection. Clinical severity of pneumonia can be c...
Timoney PJ, McCollum WH, Roberts AW, McDonald MJ.Clinical cases of equine arteritis virus infection have not been diagnosed in Kentucky since 1984, and there has been no indication that any of the horses involved in the 1984 epizootic have since been responsible for spread of the disease to horses in other states or other countries. Cases of abortion caused by naturally acquired infection with this virus have not been confirmed in 1984 or 1985. Neither field nor vaccine strains of equine arteritis virus have been shown to induce teratologic abnormalities or the carrier state in foals born to infected or vaccinated mares. The carrier stallion...
Mayr A.Among all infectious diseases affecting horses, respiratory disease pose the greatest threat to horses kept in stables, horses used for breeding and race horses. Here a distinction should be made between the so-called monocausal infectious diseases (so-called Henle-Koch postulates) and multicausal infectious diseases which are the result of the synergistic interaction of different processes, that alone do not lead to disease. There is no clearcut distinction between the two groups. The most important monocausal respiratory infections of horses are caused by equine influenza virus (subtypes 1 a...
Short CR, Horner MW, Blay PK, Moss MS, Edington N, Clarke CR.Several studies conducted during the past few years have shown that the pharmacokinetics of a variety of drugs may be altered following viral infection or vaccination. The elimination of drugs which are extensively metabolized, such as theophylline, may be prolonged, especially following exposure to RNA viruses such as Type A influenza or similar orthomyxoviruses. The purpose of this study was to determine whether vaccination of horses with equine influenza virus affected pharmacokinetic parameters describing the distribution and elimination of intravenously administered theophylline. Three th...
Klei TR.This article will focus on current information available on the equine immune response to helminth parasites as it relates to acquired resistance, hypersensitivity reactions, and vaccine development.
Frymus T, Kita J, Woyciechowska S, Ganowicz M.On 6 farms with a history of EHV-1 abortions the overall prevalence of losses due to abortion, stillbirth and neonatal foal mortality during 5 foaling seasons preceding the introduction of vaccination against EHV-1 were compared with corresponding data for 8 subsequent seasons in which all horses were immunized with a modified live EHV-1 vaccine. Although both sporadic and epizootic EHV-1 abortions occurred in immunized mares, the numbers of foetal and neonatal foal losses decreased significantly (chi 2 = 15.75; p less than 0.001) from 11.8% (343 of 2897 pregnancies) during the seasons 1969-19...
Timoney JF, Eggers D.An indirect test based on horse blood was used to study bactericidal responses of the horse to Streptococcus equi following infection or vaccination. Bactericidal antibody appeared in convalescent sera between two and four weeks and high titres were usually attained by eight weeks. Infection without clinical evidence of abscessation was also effective in eliciting strong bactericidal responses. Serum bactericidal activity of horses either recovered from strangles or immunised with commercial bacterin had declined eight months after vaccination. However, horses that developed strangles eight to...
Blythe LL, Mattson DE, Lassen ED, Craig AM.Neutralizing antibodies against equine herpesvirus 1 were measured in serum and cerebrospinal fluid of 16 horses and ponies from a closed herd both before and after vaccination with modified live equine herpesvirus 1. These titers were also measured in 22 neurologically normal and 15 neurologically abnormal horses at a teaching hospital. Animals from the closed herd had prevaccination serum titers up to 1:8 and postvaccination serum titers up to 1:128. Horses from the teaching hospital had serum titers up to 1:64. Cerebrospinal fluid titers were not detected in the vaccinated horses or the neu...
Kemen MJ, Frank RA, Babish JB.An outbreak of an influenza-like illness affected approximately 1/3 of the 1050 race horses stabled at a standardbred racetrack and resulted in a 3-day suspension of racing. A/Equi-2 influenza virus was isolated from 1 affected horse and 8 of 10 horses sampled seroconverted. Threshold protective levels of HI antibody against A/Equi-2 influenza virus were not demonstrated in unaffected horses. Resistance in unaffected horses was assumed to result from other factors following previous exposure. Few of the horses had been vaccinated against equine influenza. It was felt that an outbreak of this m...
Burrows R, Goodridge D, Denyer MS.Vaccinated yearlings , two-year-old and in-foal pony mares with appropriate controls were exposed to aerosols of a subtype 1 virus one to two months after two or three vaccinations; all became infected. No obvious differences in the febrile responses, clinical signs and subsequent abortions were found between vaccinated and control mares. All vaccinated yearlings and two-year-old ponies developed a febrile respiratory disease but this was less severe than that suffered by the controls and the amounts and duration of virus shedding were reduced.
Johnson JA, Prescott JF, Markham RJ.Six foals were inoculated intrabronchially with a suspension of Corynebacterium equi. Six weeks before this challenge, three foals were vaccinated with a C. equi bacterin. Three foals were unvaccinated controls. All foals developed a severe bronchopneumonia in the inoculated lung, indicating that vaccination was not protective. Three foals (two vaccinated, one control) were killed eight to nine days after infection. One control died on day 9 with lesions of disseminated intravascular coagulation. The remaining two foals (one vaccinated, one control) were killed on day 17. C. equi was cultured ...
The Journal of hygieneJune 1, 1983
Volume 90, Issue 3 371-384 doi: 10.1017/s0022172400029004
Wood JM, Mumford J, Folkers C, Scott AM, Schild GC.Serological responses to three bivalent aqueous equine influenza vaccines of different potency and an adjuvanted bivalent vaccine containing inactivated A/equine/Prague/56 (H7N7) and A/equine/Miami/63 (H3N8) viruses, were examined in seronegative ponies. Potencies of the vaccines, measured by single-radial-diffusion tests, ranged from 4 to 56 micrograms of haemagglutinin (HA) antigen activity/virus strain per dose. Serological responses to vaccination were examined by haemagglutination-inhibition (HI) and single-radial-haemolysis (SRH) tests. Four weeks after a primary dose, HI responses to bo...
The Journal of hygieneJune 1, 1983
Volume 90, Issue 3 385-395 doi: 10.1017/s0022172400029016
Mumford J, Wood JM, Scott AM, Folkers C, Schild GC.Forty ponies immunized with inactivated virus vaccine containing A/equine/Miami/63 (H3N8) virus and six unvaccinated, seronegative ponies were experimentally challenged with a representative of recent equine H3N8 virus isolates, A/equine/Newmarket/79. All unvaccinated ponies became infected as judged by virus excretion, febrile responses and antibody responses, but only two of the vaccinated ponies were fully protected. Pre-challenge antibody levels to A/Newmarket/79 virus detected by single radial haemolysis (SRH) correlated well with the degree of clinical protection but the levels required ...
Hinshaw VS, Naeve CW, Webster RG, Douglas A, Skehel JJ, Bryans J.Influenza outbreaks involving viruses of the H3N8 subtype (equine 2) often occur in vaccinated horses. For this reason, a series of influenza viruses of the H3N8 subtype were examined to determine if antigenic variation could be detected in isolates during the period 1963-81. Antigenic analyses with post-infection ferret sera and monoclonal antibodies showed that the haemagglutinins of recent isolates were antigenically distinguishable from the prototype A/eq/Miami/1/63 and that antigenically distinguishable groups of equine 2 viruses co-circulate in the horse population. Based on these studie...
Campbell TM, Studdert MJ.An inactivated equine adenovirus type 1 (EAdV1) vaccine was administered to 4 horses. The horses had virus-neutralizing (VN) antibody titers before they were vaccinated, but developed higher VN antibody titers in response to vaccination. Nonvaccinated control horses did not show increases in VN antibody during the study, indicating that any increase in antibody titer in vaccinated horses was a result of vaccination and not due to an EAdV1 epizootic during the study. Specific EAdV1 in vitro lymphocyte blastogenesis (LB) was evaluated, using lymphocytes from 4 vaccinated and 2 control horses. Ho...
Pradhan SS, Balena V, Bera BC, Anand T, Khetmalis R, Madhwal A, Kandasamy S, Pavulraj S, Bernela M, Mor P, Tripathi BN, Virmani N.Equine herpesvirus type 1 (EHV1) is a ubiquitous viral pathogen infecting the equine population worldwide. EHV1 infection causes respiratory illness, abortion, neonatal foal mortality, and myeloencephalopathy. The currently available modified live EHV1 vaccines have safety and efficacy limitations. The two mutant EHV1 viruses (vToH-DMV (∆IR6/gE) and vToH-QMV (∆IR6/UL43/gE/UL56)), generated by the deletion of genes responsible for virulence (gE and IR6) and immunosuppression (uL43 and uL56), have been previously characterized by our group and found to generate good immune responses. The pre...
Yuen NKY, Harrison JJ, Wang ASW, McMahon IE, Habarugira G, Coyle MP, Bielefeldt-Ohmann H.An incursion and outbreak of Japanese encephalitis virus (JEV) was reported in Australia in 2021 and 2022, respectively. There was speculation that JEV may have been circulating in Australia unknowingly prior to the detection. In this study, we determined sero-prevalence and transmission of West Nile virus (WNV), Murray Valley encephalitis virus (MVEV) and JEV, prior to and post JEV incursion in a sentinel equine population in south-east Queensland (SEQ), Australia, using blocking ELISAs (screening test) and virus neutralisation test (confirmatory). Serum samples collected between 2018 and 202...
Egenvall A, Valle PS, Hoffman R, Höglund OV, Byström A, Lönnell C, Bonnett BN.In a 10-15-year period, veterinary clinics in Sweden and Norway, as elsewhere, have undergone widespread corporatisation. High veterinary care costs have received attention in the lay press and from competition authorities. Whether corporate chains and independent clinics differ in price levels and how clinic characteristics, such as on-call service, affect pricing is not well-documented. The aim was to analyse prices levels and price changes for various diagnoses/procedures for dogs, cats, and horses from clinics in Norway and Sweden and to examine the influence of affiliation (corporate chai...
Zientara S.After a brief historical account of the outbreak of infectious arteritis of horses which occurred in 1984 in Kentucky (United States of America), the author reports on the present state of knowledge concerning the organisation of the genome of the virus. Clinical signs of the disease are described, as well as modes and routes of transmission. Finally, currently-available vaccination procedures are discussed and their value is assessed.
Kihm U, Ackermann M.The objective of the present review was to summarize current knowledge of African horse sickness (AHS), based on available literature (which is nonetheless relatively scant) and recent information obtained from the O.I.E. Brief description is made of the biology of AHS virus (an arbovirus, transmitted by Culicoides imicola), isolation of the agent, diagnosis by serotyping procedures, and preventive measures (such as protection of horses from insect infestation, or vaccination programs) which may be taken. The recent outbreaks in Spain, Portugal, and Morocco, have demonstrated that much more re...
Willsallen H, Yang PJ, Jacobs KA.This case report describes the accidental intramuscular administration of 20 mL Gudair® vaccine to a 7-year-old Standardbred mare and successful treatment of the resulting inflammatory reaction by radical surgical resection.
Schüle E.Because of the growing interest in animal health and welfare in breeding and sport--specially in the horse--the regulation of the German Riding Association (FN) was updated. The result--the LPO 2000--refer more functions to the veterinarian. At first the permanent presence of the vet is necessary, at second he controls the correct, new installed vaccination against influenza-virus. The functions of vet-check, general horse-control and doping are wide up in number and consultation. For this the veterinarian must decree about much experience and good preparation. The organisations of the veterin...