Protective efficacy of multivalent replication-abortive vaccine strains in horses against African horse sickness virus challenge. Issue 33 (24th July 2017)

• Record Type: Journal Article
• Authors: Lulla, Valeria; Losada, Andres; Lecollinet, Sylvie; Kerviel, Adeline; Lilin, Thomas; Sailleau, Corinne; Beck, Cecile; Zientara, Stephan; Roy, Polly
• Is Part Of: Vaccine. Volume 35:Issue 33(2017)
• Page Start: 4262
• Page End: 4269
• Publication Date: 2017-07-24
• Subjects: AHSV -- Orbivirus -- Reverse genetics -- Novel vaccine; Vaccines -- Periodicals; 615.372
• DOI: 10.1016/j.vaccine.2017.06.023
• Languages: English
• ISSNs: 0264-410X

Abstract

Highlights: AHSV is an emerging insect-borne virus. The mortality rate of infected horses is often up to 90% New generation of vaccines are made using reveres genetics. These vaccines are replication abortive but highly immunogenic. Both monovalent and multivalent vaccines are protective in ponies. Abstract: African horse sickness virus (AHSV) is an orbivirus, a member of the Reoviridae family. Nine different serotypes have been described so far. AHSV is vectored by Culicoides spp. to equids, causing high mortality, particularly in horses, with considerable economic impacts. For development of a safe attenuated vaccine, we previously established an efficient reverse genetics (RG) system to generate Entry Competent Replication-Abortive (ECRA) virus strains, for all nine serotypes and demonstrated the vaccine potential of these strains in type I interferon receptor (IFNAR)-knockout mice. Here, we evaluated the protective efficacies of these ECRA viruses in AHSV natural hosts. One monoserotype (ECRA.A4) vaccine and one multivalent cocktail (ECRA.A1/4/6/8) vaccine were tested in ponies and subsequently challenged with a virulent AHSV4. In contrast to control animals, all vaccinated ponies were protected and did not develop severe clinical symptoms of AHS. Furthermore, the multivalent cocktail vaccinated ponies produced neutralizing antibodies against all serotypes present in the cocktail, and a foal born during the trial was healthy and had no viremia. These results validate the suitability of these ECRA strains as a new generation of vaccines for AHSV.