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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.

Mongolia is a large landlocked country in central Asia and has one of the highest per capita livestock ratios in the world. During 2017 reported Foot and Mouth disease (FMD) outbreaks in Mongolia increased considerably, prompting widespread disease control measures. This study estimates the socio-economic impact of FMD and subsequent control measures on Mongolian herders. The analysis encompassed quantification of the impact on subsistence farmers' livelihoods and food security and estimation of the national level gross losses due to reaction and expenditure during 2017. Data were collected from 112 herders across eight Provinces that reported disease. Seventy of these herders had cases of FMD, while 42 did not have FMD in their animals but were within quarantine zones. Overall, 86/112 herders reported not drinking milk for a period of time and 38/112 reduced their meat consumption. Furthermore, 55 herders (49.1%) had to borrow money to buy food, medicines and/or pay bills or bank loans. Among herders with FMD cases, the median attack rate was 31.7%, 3.8% and 0.59% in cattle, sheep and goats respectively, with important differences across Provinces. Herders with clinical cases before the winter had higher odds of reporting a reduction in their meat consumption. National level gross losses due to FMD in 2017 were estimated using government data. The estimate of gross economic loss was 18.4 billion Mongolian-tugriks (US$7.35 million) which equates to approximately 0.65% of the Mongolian GDP. The FMD outbreaks combined with current control measures has negatively impacted herders' livelihoods (including herders with and without cases of FMD) which is likely to reduce stakeholder advocacy. Possible strategies that could be employed to ameliorate the negative effects of the current control policy were identified. The findings and approach are relevant to other FMD endemic regions aiming to control the disease.