The Merger (Schedule of company’s consolidated statement of operations and unaudited proforma information) (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Business Acquisition [Line Items]
General and administrative expenses	$ 1,973,000	$ 2,082,000	$ 4,144,000	$ 3,462,000
Net loss	(4,710,000)	$ (4,199,000)	(9,788,000)	$ (7,938,000)
AmpliPhi Biosciences Corporation [Member]
Business Acquisition [Line Items]
Research and development expenses	138,000		260,000
General and administrative expenses	346,000		570,000
Net loss	$ 484,000		$ 830,000