Middle East Respiratory Syndrome coronavirus (MERS-CoV) is an emerging virus that infects humans and camels with no approved antiviral therapy or vaccine. Some vaccines are in development for camels as a one-health intervention where vaccinating camels is proposed to reduce human viral exposure. This intervention will require an understanding of the prior exposure of camels to the virus and appropriate vaccine efficacy studies in camels. We conducted a cross sectional seroprevalence study in young dromedary camels to determine the rate of MERS-CoV seropositivity in young camels. Next, we utilised naturally infected camels as a natural challenge model that can be used by co-housing these camels with healthy naive camels in a ratio of 1 to 2. This model is aimed to support studies on natural virus transmission as well as evaluating drug and vaccine efficacy. We found that 90% of the screened camels have pre-existing antibodies for MERS-CoV. In addition, the challenge model resulted in MERS-CoV transmission within 48 h with infections that continued for 14 days post challenge. Our finding suggests that the majority of young dromedary camels in Saudi Arabia are seropositive and that naturally infected camels can serve as a challenge model to assess transmission, therapeutics, and vaccine efficacy.

中文翻译：

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基于自然感染的骆驼的MERS-CoV挑战感染模型。

中东呼吸综合症冠状病毒（MERS-CoV）是一种新兴病毒，未经批准的抗病毒治疗或疫苗即可感染人和骆驼。骆驼的一些疫苗正在开发中，作为一种单人干预措施，其中提议对骆驼进行疫苗接种以减少人体病毒暴露。这种干预措施需要了解骆驼事先接触该病毒的情况，并需要对骆驼进行适当的疫苗功效研究。我们对幼年单峰骆驼进行了血清横断面研究，以确定幼年骆驼的MERS-CoV血清阳性率。接下来，我们将自然感染的骆驼用作自然挑战模型，可以将这些骆驼与健康的幼稚骆驼以1比2的比例共居在一起使用。该模型旨在支持有关天然病毒传播的研究以及评估药物和疫苗的功效。我们发现，筛查的骆驼中有90％具有针对MERS-CoV的预先存在的抗体。此外，攻击模型导致MERS-CoV在48小时内传播，感染在攻击后持续14天。我们的发现表明，沙特阿拉伯的大多数幼年单峰骆驼都是血清阳性的，自然感染的骆驼可以作为评估传播，治疗和疫苗功效的挑战模型。