Extended Data Table 3.

Scoring system for mice study

Parameter	Points	Observations
General condition	0.0	Alert, Live, active, reacts to their surroundings
	0.1	Slow, weak, less active
	0.4	Immobile, limited or no voluntary movement, lying motionless
The eyes	0.0	Clear and clean eyes
	0.1	Slight discharge around eyes and nose
	0.4	Discharge on the face and/or legs and paws. Swollen eyes
Movement and posture	0.0	Normal
	0.1	Cannot fully coordinate movements
	0.4	One or more of the following: Marked incoordination, hunched posture or back, lying motionless, severe lameness
Piloerection	0.0	Fur smooth and well-groomed
	0.1	Mild piloerection
	0.4	Severe piloerection

Mice infected with CCHFV reaching the human Endpoint score fixed to 0.8 points according to Karolinska Institutet were euthanized.