Correction: Durán-Ferrer et al. Clinical, Virological and Immunological Responses After Experimental Infection with African Horse Sickness Virus Serotype 9 in Immunologically Naïve and Vaccinated Horses. Viruses 2022, 14, 1545.

Overview

• This study investigated how horses respond clinically, virologically, and immunologically after being experimentally infected with African Horse Sickness Virus (AHSV) serotype 9, comparing horses that were immunologically naïve with those that were vaccinated.

Background

• African Horse Sickness Virus (AHSV): AHSV is a serious viral disease affecting horses, often leading to severe respiratory and circulatory symptoms with high mortality rates.
• Serotype 9: Refers to a specific variation of AHSV that presents distinctive antigenic properties influencing vaccine effectiveness and immune response.
• Need for Study: Understanding the clinical signs, viral dynamics, and immune responses in both vaccinated and unvaccinated horses aids in evaluating vaccine efficacy and provides better insight for disease control strategies.

Study Design

• Subjects: The study included two groups of horses—immunologically naïve (unvaccinated) and vaccinated animals.
• Experimental Infection: Both groups were deliberately infected with AHSV serotype 9 under controlled conditions.
• Data Collection: Researchers monitored clinical signs, virus levels (virological response), and immune system indicators (immunological response) over time after infection.

Key Findings

• Clinical Responses: The unvaccinated horses exhibited more severe disease symptoms consistent with African Horse Sickness, while vaccinated horses had reduced clinical signs, indicating partial or full protection conferred by vaccination.
• Virological Data: Virus was detected at higher levels for a longer duration in immunologically naïve horses. Vaccinated horses showed lower viral loads, suggesting effective suppression of viral replication.
• Immunological Responses: Vaccinated horses demonstrated an accelerated and stronger immune response, likely mediated through the presence of neutralizing antibodies and cellular immunity from vaccination.
• Implications: The study supports the use of vaccination to mitigate AHSV infection severity and viral shedding, helping to prevent disease outbreaks and limiting virus transmission.

Conclusions and Significance

• The research confirms that vaccination alters the clinical course of African Horse Sickness Virus serotype 9 infection positively, reducing illness severity and viral presence in horses.
• Immunologically naïve horses remain at high risk for severe disease and contribute to virus circulation.
• The comprehensive clinical, virological, and immunological data provided offer valuable insights for improving vaccine strategies and managing African Horse Sickness in equine populations.
• This work supports ongoing development of vaccines and informs veterinary practices related to AHSV control and prevention in vulnerable horse populations.