CLEAN : British Ebola sufferer receiving experimental drug

The video provides an update on a patient receiving the tzemach treatment for Ebola. The patient is showing resilience, engaging with medical staff, and is in good spirits. However, the course of Ebola is unpredictable, and the next few days are critical for the patient's recovery.

What is noted about the course of the Ebola infection?

Why are the next few days critical for the young man?