USMLE Step 1 MCQ Question And Answer With Explanation Get link Facebook X Pinterest Email Other Apps Ebola Virus Disease MCQ Q3. Ebola virus disease affects mainly which system? A) Nervous system B) Circulatory system C) Immune system D) Digestive system Check Answer ✔ Correct Answer: C) Immune system Explanation: Ebola virus primarily targets and disrupts the immune system, especially monocytes, macrophages, and dendritic cells. This immune suppression leads to an overwhelming inflammatory response, which causes many of the severe symptoms associated with the disease.