Department of Infectious Disease Research, King Abdullah International Medical Research Center, Riyadh, Saudi Arabia.
King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia.
Virol J. 2020 Jun 17;17(1):77. doi: 10.1186/s12985-020-01347-5.
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.
中东呼吸综合征冠状病毒（MERS-CoV）是一种新兴的感染人类和骆驼的病毒，目前尚无批准的抗病毒疗法或疫苗。一些疫苗正在开发中，作为一种“同一健康”干预措施，建议给骆驼接种疫苗以减少人类的病毒暴露。这种干预措施需要了解骆驼以前对该病毒的暴露情况，以及在骆驼中进行适当的疫苗功效研究。
我们在年轻的单峰驼中进行了一项横断面血清流行率研究，以确定年轻骆驼中 MERS-CoV 血清阳性率。接下来，我们利用自然感染的骆驼作为自然挑战模型，通过将这些骆驼与健康的、未感染的骆驼以 1:2 的比例共同饲养来实现。该模型旨在支持对自然病毒传播的研究，以及评估药物和疫苗的功效。
我们发现，90%的筛查骆驼都存在针对 MERS-CoV 的预先存在的抗体。此外，该挑战模型导致 MERS-CoV 在 48 小时内传播，感染持续 14 天。
我们的发现表明，沙特阿拉伯的大多数年轻单峰驼都是血清阳性的，而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。
