No abstract

Equine encephalosis virus (EEV) is the cause of equine encephalosis. The disease is similar to mild forms of African horse sickness (AHS) and the two diseases are easily confused. Laboratory identification and serotyping of EEV is based on viral isolation in BHK-21 cells and a viral plaque inhibition neutralization test. These procedures are time-consuming and therefore a more rapid diagnostic assay for EEV that can distinguish EEV from African horse sickness virus (AHSV) infections was developed.The S7 (VP7) gene from 38 EEV isolates representing all seven serotypes was amplified and sequenced. A conserved region at the 5' end of the gene was identified and used to design groupspecific EEV primers and a TaqMan® MGB™ hydrolysis probe.The efficiency of the EEV real-time RT-PCR assay was 81 %. The assay was specific, as it did not detect any of the nine serotypes of AHSV, nor 24 serotypes of bluetongue virus (BTV) and sensitive, with a 95 % limit of detection of 10 2.9 TCID 50 /ml blood (95 % confidence interval: 10 2.7 -10 3.3).The real-time format was selected because of its convenience, sensitivity and ability to produce results rapidly.1 Keywords: equine encephalosis virus; real time RT-PCR; orbivirus; diagnostic assay; group-specific; VP7 Highlights The S7 genes of 38 EEV isolates were sequenced.  A real-time RT-PCR assay for equine encephalosis virus was developed.  The 95% limit of detection of the EEV assay was 10 2.9 TCID 50 . The assay was specific for EEV and did not detect other orbiviruses (BTV, AHSV).

The effective control of foot-and-mouth disease (FMD) relies strongly on the separation of susceptible and infected livestock or susceptible livestock and persistently infected wildlife, vaccination, and veterinary sanitary measures. Vaccines affording protection against multiple serotypes for longer than six months and that are less reliant on the cold chain during handling are urgently needed for the effective control of FMD in endemic regions. Although much effort has been devoted to improving the immune responses elicited through the use of modern adjuvants, their efficacy is dependent on the formulation recipe, target species and administration route. Here we compared and evaluated the efficacy of two adjuvant formulations in combination with a structurally stabilized SAT2 vaccine antigen, designed to have improved thermostability, antigen shelf-life and longevity of antibody response. Protection mediated by the Montanide ISA 206B-adjuvanted or Quil-A Saponin-adjuvanted SAT2 vaccines were comparable. The Montanide ISA 206B-adjuvanted vaccine elicited a higher SAT2 neutralizing antibody response and three times higher levels of systemic IFN-γ responses at 14- and 28-days post-vaccination (dpv) were observed compared to the Quil-A Saponin-adjuvanted vaccine group. Interestingly, serum antibodies from the immunized animals reacted similarly to the parental vaccine virus and viruses containing mutations in the VP2 protein that simulate antigenic drift in nature.