Table. Most commonly adapted aspects to sentinel surveillance systems by country and degree of change, during the first pandemic phase, March–September 2020.

Country	Degree of changes
	Swab collection		Laboratories	Data collection and digital technology
	Patient pathway	Sampling criteria
Sweden	Minimal	None	None	None
Netherlands	Modest	None	None	None
France	Modest	Modest	Modest	Modest
England	Modest	Modest	Modest	Minor
Scotland	Major	Modest	Major	Major
Portugal	Major	Major	Major	Modest
Spain	Major	Major	Major	Major