Seroprevalence of Equine Herpesvirus 1 (EHV-1) and Equine Herpesvirus 4 (EHV-4) in the Northern Moroccan Horse Populations.
Authors: El Brini Zineb, Fassi Fihri Ouafaa, Paillot Romain, Lotfi Chafiqa, Amraoui Farid, El Ouadi Hanane, Dehhaoui Mohamed, Colitti Barbara, Alyakine Hassan, Piro Mohammed
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary: EHV-1 and EHV-4 Seroprevalence in Northern Morocco Equine herpesviruses remain a significant concern in many regions, yet epidemiological data gaps persist, particularly in North Africa. El Brini and colleagues conducted the first comprehensive seroprevalence survey of EHV-1 and EHV-4 in Moroccan horse populations in nearly a quarter-century, testing 405 animals (163 unvaccinated, 242 vaccinated with monovalent EHV-1 vaccine) using type-specific ELISA and virus neutralisation tests to establish current disease burden and vaccine-induced immunity. EHV-1 antibodies were detected in 12.8% of unvaccinated horses and 21.8% of vaccinated animals, whilst EHV-4 seropositivity was near-universal across both groups; critically, vaccinated horses showed surprisingly modest neutralising antibody titres (mean 1:49 for EHV-1, 1:45 for EHV-4), raising questions about vaccine efficacy under field conditions. These findings indicate that both viruses are entrenched in the region with considerable geographic variation, and the weak antibody response to monovalent vaccination suggests that current protocols may be suboptimal, necessitating urgent review of vaccination strategies and implementation of rigorous biosecurity protocols to mitigate transmission risk in competing and breeding populations across Morocco.
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Practical Takeaways
- •Both EHV-1 and EHV-4 are actively circulating in northern Morocco; biosecurity protocols should reflect active endemic disease presence
- •Current monovalent EHV-1 vaccines generate suboptimal antibody titers in field conditions; vaccination protocols and/or vaccine formulations may need review for improved protection
- •Serological testing before and after vaccination should be considered to assess individual immune response, particularly given the low titers observed
Key Findings
- •12.8% of unvaccinated horses tested seropositive for EHV-1, compared to 21.8% of vaccinated horses in northern Morocco
- •100% of all tested samples were seropositive for EHV-4 using type-specific ELISA
- •Vaccinated horses receiving monovalent EHV-1 vaccine showed low mean antibody titers of 1:49 for EHV-1 and 1:45 for EHV-4
- •EHV-1 and EHV-4 are endemic in northern Moroccan horse populations with regional prevalence differences