Orf Virus Genome Sequencing

Abstract

Orf virus (ORFV) is an ancient Parapoxvirus that causes substantial economic loss worldwide to sheep and goat producers. This virus causes a disease known as Contagious Ecthyma or more commonly “Soremouth” because it most commonly presents itself on the lips and mouth of sheep and goats. Soremouth makes it difficult for animals to eat and drink, therefore leading to weight loss or failure to gain weight resulting in production losses. The primary victims of the disease are suckling lambs and kid goats. These animals have immature immune systems increasing their risk of infection and are at risk for dehydration and weight loss as the lesions in the mouth affect their ability to nurse. ORFV is a zoonotic virus that can transfer from sheep and goat to humans and other species. ORFV has immunomodulatory capabilities as the virus encodes a synthetic interleukin-10, an immune down-regulator. It also inhibits other immune activation pathways such as the Toll-like receptors. ORFV is an ideal target for vaccination because of its immunomodulatory features and because the infection is generally self-limiting. A vaccine is currently under development by Texas Vet Lab, Inc. and the genome of the virus used for the development of this vaccine is sequenced and examined here. The goal of this study was to allow comparisons between the current vaccine candidate and other sequenced ORFV genomes.