Consolidated Statements of Operations - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Consolidated Statements of Operations [Abstract]
Grant revenue	$ 1,168,000	$ 31,000	$ 2,234,000	$ 31,000
Operating expenses
Research and development	5,225,000	2,648,000	9,575,000	5,398,000
General and administrative	2,139,000	1,973,000	4,290,000	4,144,000
Total operating expenses	7,364,000	4,621,000	13,865,000	9,542,000
Loss from operations	(6,196,000)	(4,590,000)	(11,631,000)	(9,511,000)
Other income (expense)
Interest income	2,000	22,000	4,000	24,000
Interest expense	0	(142,000)	(62,000)	(301,000)
Total other income (expense), net	2,000	(120,000)	(58,000)	(277,000)
Net loss	$ (6,194,000)	$ (4,710,000)	$ (11,689,000)	$ (9,788,000)
Per share information:
Net loss per share, basic and diluted (in dollars per share)	$ (0.25)	$ (0.26)	$ (0.52)	$ (0.68)
Weighted average shares outstanding, basic and diluted	24,762,818	18,347,051	22,622,477	14,399,399