Efficacy of a foot-and-mouth disease vaccine against a heterologous SAT1 virus challenge in goats. Issue 24 (19th May 2020)

• Record Type: Journal Article
• Authors: Lazarus, D.D.; Peta, F.; Blight, D.; Van Heerden, J.; Mutowembwa, P.B.; Heath, L.; Blignaut, B.; Opperman, P.A.; Fosgate, G.T.
• Is Part Of: Vaccine. Volume 38:Issue 24(2020)
• Page Start: 4006
• Page End: 4015
• Publication Date: 2020-05-19
• Subjects: FMD -- Vaccination -- Dosage -- Clinical protection -- Goats; Vaccines -- Periodicals; 615.372
• DOI: 10.1016/j.vaccine.2020.04.014
• Languages: English
• ISSNs: 0264-410X

Abstract

Highlights: Domestic goats are important FMD susceptible host species. However, their role in the epidemiology of the disease is poorly understood. A high-potency FMD vaccine induced clinical protection in goats against a heterologous challenge with FMDV SAT1. Abstract: Goats are susceptible to infection with foot-and-mouth disease virus (FMDV), but their role in the epidemiology of the disease and response to vaccination is poorly understood. In southern Africa, FMDV serotypes Southern African Territories (SAT) 1, 2 and 3 are known to be endemic. In this study, we evaluated the efficacy of a pentavalent FMD vaccine in goats against heterologous challenge with a pool of field SAT1 FMDV. Forty FMD sero-negative goats (6–12 months of age) of mixed sexes were randomly allocated to one of five treatment groups: full cattle dose (2 ml), 1/3rd (0.67 ml), 1/6th (0.33 ml), 1/12th (0.16 ml) or unvaccinated placebo control. Goats were vaccinated with an inactivated pentavalent FMD vaccine containing serotypes SAT1, SAT2 and SAT3 on day 0 and revaccinated at day 20 post vaccination. Thereafter, thirty-four goats were challenged by tongue inoculation at day 41 post-vaccination using 10 4.57 50% tissue culture infective dose (TCID50 ) FMDV SAT1 pool. Animals were examined daily and clinical signs were scored. Rectal temperatures were measured daily, with temperatures ≥40 °C defined as fever. Clinical specimens (nasal, oral and rectal swabs) were collected on days 0, 2, 4 and 6 post challenge. Viral shedding was determined using reverse-transcriptase real-time PCR. None of the goats vaccinated with the full cattle dose developed secondary lesions. All vaccinated groups had lower temperatures compared to the unvaccinated controls (P < 0.001). Based on RT-PCR results, goats in the unvaccinated control group shed more virus compared to all groups except for 1/12th (P < 0.05), while goats in the full dose group shed less virus than goats in the 1/12th and the unvaccinated control group (P < 0.05). The results suggest that the 1/3rd (0.67 ml) dose of the vaccine is sufficient to reduce viral shedding after heterologous challenge with a FMDV SAT1 pool.