The Merger (Schedule of company’s consolidated statement of operations and unaudited proforma information) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Research and development expenses	$ 9,824,000	$ 8,372,000
General and administrative expenses	9,265,000	2,519,000
Sale of Slovenia (Note 6)	663,000
Net loss	(19,479,000)	(16,702,000)
Business Acquisition, Pro Forma Information [Abstract]
Net loss	(21,335,000)	$ (27,818,000)
AmpliPhi Biosciences Corporation [Member]
Business Acquisition [Line Items]
Research and development expenses	1,321,000
General and administrative expenses	1,917,000
Sale of Slovenia (Note 6)	663,000
Net loss	$ 3,901,000