RESEARCH Infection of equine monocy o

Full list of author information is available at the end of the articlelineage in vivo [1,2]. The clinical manifestation of equine infectious anemia (EIA), which is caused by EIAV infection, can be divided into an acute phase, a chronic phase, and an asymptomatic phase. The acute and chronic phases ex-hibit typical viremia accompanied by a high fever, anemia, thrombocytopenia, edema, and weight loss. The infected equines usually enter the life-long asymptomatic carrier state after 8–12 months. However, the virus maintains a low level of stable replication in tissues that are enriched EIAV-infected equines become asymptomatic carriers due to immune control of the infection, EIAV has become a unique lentivirus model for studies investigating the im-mune control of lentivirus infection and its pathogenesis. In addition, most asymptomatic EIAV-infected horses demonstrate a significant resistance to infections caused by different pathogenic EIAV strains [1,5]. This finding sug-gests that the EIAV system can provide a model for study-ing key immune factors that are involved in resistance to lentiviral infection, which can be used for the research and development of preventive lentivirus vaccines. EIAVFDDV13 is an attenuated EIAV vaccine strain that in-duces immune protection in approximately 80 % of vacci