Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($)	Mar. 31, 2021	Dec. 31, 2020
ASSETS
Cash and cash equivalents	$ 20,842,782	$ 9,883,796
Grant funds and other receivables		182,663
Prepaid expenses and other current assets	118,430	168,689
Total current assets	20,961,212	10,235,148
Property and equipment, net	143,224	147,741
Deposits	11,010	11,010
Total assets	21,115,446	10,393,899
Current liabilities:
Accounts payable	232,482	267,702
Accrued expenses	36,623	359,281
Current portion of notes payable	182,844	183,326
Total current liabilities	451,949	810,309
Note payable, net of current portion	12,157	14,738
Total liabilities	464,106	825,047
Commitments (Note 8)
Stockholders’ equity:
Common stock, $.001 par value; Authorized shares – 600,000,000; Issued and outstanding shares – 6,315,467 and 3,834,095 at March 31, 2021 and December 31, 2020, respectively	6,315	3,834
Additional paid-in capital	67,937,289	55,294,504
Accumulated deficit	(47,368,359)	(45,805,581)
Total stockholders’ equity	20,651,340	9,568,852
Total liabilities and stockholders’ equity	21,115,446	10,393,899
Series B Convertible Preferred Stock [Member]
Stockholders’ equity:
Preferred Stock, $.01 par value: Authorized shares – 10,000,000: Series B convertible preferred stock, $1,000 stated value; Authorized shares – 10,000,000; 100 shares issued and outstanding at March 31, 2021 and December 31, 2020, respectively	$ 76,095	$ 76,095

Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

Name:	us-gaap_AccountsPayableCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Carrying value as of the balance sheet date of obligations incurred and payable, pertaining to costs that are statutory in nature, are incurred on contractual obligations, or accumulate over time and for which invoices have not yet been received or will not be rendered. Examples include taxes, interest, rent and utilities. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).