Seroprevalence of Equine Herpesvirus 1 (EHV-1) and Equine Herpesvirus 4 (EHV-4) in the Northern Moroccan Horse Populations

This study reports the first equine herpesvirus-1 (EHV-1) and equine herpesvirus-4 (EHV-4) seroprevalence investigation in horse populations of Morocco in 24 years. It also aims to determine antibody titers in horses vaccinated under field conditions with a monovalent EHV-1 vaccine. Blood samples were collected from 405 horses, including 163 unvaccinated and 242 vaccinated animals. They were tested using a commercial type-specific enzyme-linked immunosorbent assay (ELISA) and a virus neutralization test (VNT). Overall, 12.8% unvaccinated, and 21.8% vaccinated horses were positive for EHV-1. All samples were positive for EHV-4 when tested with the type-specific ELISA. In the vaccinated group, the VNT revealed a mean antibody titer of 1:49 for EHV-1 and 1:45 for EHV-4.

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Application of equine herpesvirus-1 vaccine inactivated by both formaldehyde and binary ethylenimine in equine

Veterinary World ◽

10.14202/vetworld.2021.1815-1821 ◽

2021 ◽

pp. 1815-1821

Author(s):

Fatma F. Warda ◽

Hala El Sawy Ahmed ◽

Nermeen G. Shafik ◽

Christine A. Mikhael ◽

Heba M. G. Abd-ElAziz ◽

...

Keyword(s):

Antibody Titer ◽

Booster Dose ◽

Economic Losses ◽

Enzyme Linked Immunosorbent Assay ◽

Equine Herpesvirus ◽

Equine Herpesvirus 1 ◽

Wide Range ◽

Group A ◽

Herpesvirus 1 ◽

Group B

Background and Aim: 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. Materials and Methods: The prepared FA/BEI-inactivated EHV-1 vaccine was adjuvanted with Alhydrogel and then evaluated by inoculation into guinea pigs, followed by comparison with the commercial inactivated EHV-1 vaccine. These two vaccines were evaluated by testing the safety and immunogenicity in horses classified into two groups. Group A was vaccinated with two doses of the prepared vaccine at a 4-week interval, while Group B was vaccinated with two doses of the commercial vaccine only. Anti-EHV-1 antibodies were detected in horse serum using enzyme-linked immunosorbent assay (ELISA) and virus neutralizing test (VNT). Results: Regarding the time required to inactivate EHV-1 vaccine, this was decreased using 0.005 M BEI and 0.0006% FA from 24 to 8 h. ELISA in Group A horses demonstrated a significant increase in EHV-1 antibody titer at 2 weeks after the booster dose compared with that for the pre-booster one, from 485 to 855 antibody titer, which then peaked at 1240 in the 3rd month post-vaccination; after that, it began to decline gradually until the 6th month. Meanwhile, in Group B, the ELISA reading increased from 420 to 790 and then peaked at 1215. The VNT mean in Group A increased from 1.1 to 2.5 within 2 weeks after administration of the booster dose, while in Group B it increased from 0.8 to 2.1. Moreover, ELISA in Group A pigs indicated mean antibody titers at the 3rd week post-inoculation of 576 for Group A and 554 for Group B. Conclusion: The inactivated EHV-1 vaccine, with fewer chemicals, was prepared in a shorter time. It is safe and also more potent to protect horses for up to 6 months against EHV-1 infection than the commercially produced vaccine.

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Serological responses of mares and weanlings following vaccination with an inactivated whole virus equine herpesvirus 1 and equine herpesvirus 4 vaccine

Veterinary Microbiology ◽

10.1016/s0378-1135(02)00100-1 ◽

2002 ◽

Vol 88 (1) ◽

pp. 13-25 ◽

Cited By ~ 20

Author(s):

C.E Foote ◽

D.N Love ◽

J.R Gilkerson ◽

J.M Whalley

Keyword(s):

Equine Herpesvirus ◽

Equine Herpesvirus 1 ◽

Herpesvirus 1 ◽

Herpesvirus 4

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Polymorphism of open reading frame 71 of equine herpesvirus-4 (EHV-4) and EHV-1

Journal of General Virology ◽

10.1099/0022-1317-83-3-525 ◽

2002 ◽

Vol 83 (3) ◽

pp. 525-531 ◽

Cited By ~ 10

Author(s):

Jin-an Huang ◽

Nino Ficorilli ◽

Carol A. Hartley ◽

George P. Allen ◽

Michael J. Studdert

Keyword(s):

Molecular Mass ◽

Variable Number ◽

Open Reading Frame ◽

Nucleotide Sequence Analysis ◽

Equine Herpesvirus ◽

Reading Frame ◽

Equine Herpesvirus 1 ◽

C Terminus ◽

Herpesvirus 1 ◽

Herpesvirus 4

Open reading frame (ORF) 71 genes of both equine herpesvirus-1 (EHV-1) and EHV-4 encode a unique glycoprotein, which has been described to vary in molecular mass from 200 to 450 kDa. Using PCR and nucleotide sequence analysis, it was shown that the ORF 71 genes of EHV-1 and EHV-4 are polymorphic due to a variable number of reiterated sequences in two regions, designated regions A and B. Region A was threonine-rich and was located near the N terminus. Region B comprised a 38 amino acid repeat near the C terminus that expanded following cell culture adaptation. Western blot analysis of viruses showed that EHV-4 gp2 was modified by glycosylation and that variation in region A resulted in the marked differences in the molecular mass of EHV-4 gp2.

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Investigations on the presence of antibodies against equine herpesvirus-1 in blood serum of foals, prior to and after colostrum intake

Veterinarski glasnik ◽

10.2298/vetgl1504195l ◽

2015 ◽

Vol 69 (3-4) ◽

pp. 195-204

Author(s):

Sasa Laus ◽

Ljubica Spasojevic-Kosic ◽

Sava Lazic ◽

Dragisa Trailovic

Keyword(s):

Blood Serum ◽

Virus Neutralization ◽

Equine Herpesvirus ◽

Blood Samples ◽

Equine Herpesvirus 1 ◽

Specific Antibodies ◽

Microtiter Plates ◽

Constant Dose ◽

Herpesvirus 1

The titer of specific antibodies against equine herpesvirus-1 in blood serum was tested in two groups of mares and their foals. The first group consisted of 12 mares, Standardbred and Serbian Trotter breed, who were vaccinated against equine herpesvirus-1 and 4 in the 5th, 7th and 9th month of pregnancy. On the contrary, 12 mares from the second group, of Lipizzaner breed, were not vaccinated. The mares? blood samples for antibodies titer investigation were taken 30, 15 and 7 days before the expected partus, then immediately after the partus, while their foals? blood samples were taken immediately after foaling, then just before colostrum intake, and finally 1, 2, 3 and 7 days later. The titer of antibodies against equine herpesvirus-1 was tested by the method of virus - neutralization, on microtiter plates with constant dose of the virus and serial double dilutions of the serum. In unvaccinated mares, titer of antibodies against equine herpesvirus-1 was either low or not present, but on the contrary, in the vaccinated ones the antibodies titer ranged from 1:32 to 1:256. In the foals originating from both vaccinated and unvaccinated there were not found specific antibodies in the serum before colostrum intake. After the colostrum intake, the values of specific antibodies against equine herpesvirus-1 significantly increased in the foals originating from the vaccinated mares, and ranged from 1:8 to 1:32.

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