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Sheeppox is a transboundary disease of small ruminants caused by infection with the capripoxvirus sheeppox virus (SPPV). Sheeppox is found in Africa, the Middle East and Asia and is characterised by fever, multifocal cutaneous raised lesions, and death. Vaccination with live attenuated capripoxvirus (CPPV) strains is an effective and widely used strategy to contol sheeppox outbreaks, however there are few reports of post-vaccination field surveillance studies. This study used a commercially available ELISA to examine quantitative and temporal features of the humoral response of sheep vaccinated with a live attenuated CPPV strain in Mongolia. 400 samples were tested using the ELISA commercial kit, and a subset of 45 samples were also tested with a virus neutralisation test (VNT). There was substantial agreement between the VNT and ELISA tests. Antibodies to CPPV were detected between 40 and 262 days post vaccination. There was no significant difference between serological status (positive / negative) and sex or age, however an inverse correlation was found between the length of time since vaccination and serological status. Animals between 90 and 180 days post-vaccination were more likely to be positive than animals greater than 180 days post vaccination. Our results show that a commercial CPPV ELISA kit is a robust and reliable assay for post CPPV vaccination surveillance in resource-restricted settings and provide temporal parameters to be considered when planning sheeppox post-vaccination monitoring programmes. This article is protected by copyright. All rights reserved.

Highlights • FMD vaccines were independently assessed using published international guidelines. • Highest titres were seen with oil-adjuvanted vaccines with a 2 dose primary course. • Lower titres were seen with aqueous vaccines requiring a boost after 3 months. • It is unknown how the lower titres observed in camels correlate with protection. • The results have important implications for vaccine policy in Mongolia., Foot-and-mouth disease (FMD) is a high impact viral disease of livestock for which vaccines are extensively used in control. Mongolia has regular incursions of FMD virus that are typically limited to the eastern region although large epidemics are occasionally reported in the normally disease-free western areas. Vaccines are imported and form an important component of the control strategy. In 2015, post-vaccination monitoring guidelines were published by the FAO-OIE recommending approaches for assessing the appropriateness of imported vaccines including small-scale immunogenicity studies. This study used these recommended approaches to guide the use of vaccine adjuvant type and the need for a one or two dose primary course in the national control programme considering cattle, sheep and Bactrian camels and also whether these vaccines were appropriate for the FMD virus lineages considered high risk to Mongolia (A/ASIA/Sea-97; O/SEA/Mya-98; O/ME-SA/PanAsia; O/ME-SA/Ind-2001). The results of these immunogenicity studies indicated that in cattle and sheep, oil-adjuvanted vaccines led to higher and more persistent neutralisation titres that were satisfactory against the target lineages if a two-dose primary course was utilised. In contrast, aqueous-adjuvanted vaccines were associated with lower titres that likely required a booster after 3 months. Levels of antibodies in Bactrian camels were significantly lower although it is unknown how these may correlate with protection under experimental or field exposure conditions. The results of this study have implications for vaccine policy in Mongolia and suggest further studies on the role of Bactrian camels in the epidemiology of FMD are necessary to indicate if further research on FMD vaccines are needed in this species.

The 2016–2017 introduction of peste des petits ruminants virus (PPRV) into livestock in Mongolia was followed by mass mortality of the critically endangered Mongolian saiga antelope and other rare wild ungulates. To assess the nature and population effects of this outbreak among wild ungulates, we collected clinical, histopathologic, epidemiologic, and ecological evidence. Molecular characterization confirmed that the causative agent was PPRV lineage IV. The spatiotemporal patterns of cases among wildlife were similar to those among livestock affected by the PPRV outbreak, suggesting spillover of virus from livestock at multiple locations and time points and subsequent spread among wild ungulates. Estimates of saiga abundance suggested a population decline of 80%, raising substantial concerns for the species’ survival. Consideration of the entire ungulate community (wild and domestic) is essential for elucidating the epidemiology of PPRV in Mongolia, addressing the threats to wild ungulate conservation, and achieving global PPRV eradication.