0001562762-23-000410 | 10-Q | XBRL Viewer

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Accrued Expenses and Other Current Liabilities (Tables)	9 Months Ended
Accrued Expenses and Other Current Liabilities (Tables)	Sep. 30, 2023
Accrued Expenses and Other Current Liabilities [Abstract]
Accrued expenses and other current liabilities	September 30, December 31, 2023 2022 Accrued external research and development $ 1,720 $ 6,904 Accrued compensation 2,689 2,568 Accrued professional fees and other 334 1,722 Accrued interest — 176 $ 4,744 $ 11,370

Prepaid Expenses and Other Current Assets	9 Months Ended
Prepaid Expenses and Other Current Assets	Sep. 30, 2023
Prepaid Expenses and Other Current Assets [Abstract]
Prepaid Expenses and Other Current Assets	5. Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets consist of the following (in thousands): September 30, December 31, 2023 2022 Clinical prepayments $ 1,762 $ 2,679 Prepaid insurance 280 1,870 Prepaid materials and supplies — 248 Deposits 240 232 Other 942 522 $ 3,224 $ 5,551 Clinical prepayments consist of amounts paid in advance to clinical research organizations (“CROs”) for expenses related to our clinical trials, primarily UB-612, and included $ 1.5 million on deposit as of September 30, 2023 that will be credited against final UB-612 trial expenses. The remaining clinical prepayment amounts are amortized to expense as earned by the CRO and clinical trial sites. Prepaid insurance consists primarily of $ 0.3 million and $ 1.6 million for the unamortized portion of the Company’s annual D&O insurance fee as of September 30, 2023 and December 31, 2022, respectively. Prepaid materials and supplies consist of amounts paid in advance related to the procurement and/or production of materials for use in the Company’s clinical trials, primarily UB-612. There were no amounts held by related parties at September 30, 2023 and $ 0.2 million at December 31, 2022.

Document and Entity Information - shares	9 Months Ended
Document and Entity Information - shares	Sep. 30, 2023	Nov. 06, 2023
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2023
Document Fiscal Period Focus	Q3
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2023
Document Transition Report	false
Entity File Number	001-41058
Entity Registrant Name	Vaxxinity, Inc.
Entity Tax Identification Number	86-2083865
Entity Incorporation, State or Country Code	DE
Entity Address, Address Line One	505 Odyssey Way
Entity Address, State or Province	FL
Entity Address, City or Town	Merritt Island
City Area Code	254
Entity Address, Postal Zip Code	32953
Local Phone Number	244-5739
Title of 12(b) Security	Class A Common Stock, par value $0.0001 per share
Trading Symbol	VAXX
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Shell Company	false
Entity Ex Transition Period	false
Entity Central Index Key	0001851657
Amendment Flag	false
Class A Common Stock [Member]
Entity Common Stock, Shares Outstanding		112,871,792
Common Class B [Member]
Entity Common Stock, Shares Outstanding		13,874,132

Property and Equipment, Net (Property and Equipment, Net) (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 16,524	$ 16,136
Less: accumulated depreciation and amortization	(5,401)	(3,624)
Property and equipment, net	11,123	12,512
Airplane [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	11,983	11,983
Laboratory And Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	3,310	3,146
Software [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	426	415
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	534	403
Facilities, Furniture And Fixtures [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	98	37
Vehicles [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	87	87
Construction In Progress [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 86	$ 65

Related Party Transactions (Schedule of Related Party Operating Activity) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Related Party Transaction [Line Items]
Prepaid expenses and other current assets	$ 3,224		$ 3,224		$ 5,551
Property and equipment, net	11,123		11,123		12,512
Current portion of note payable	929		929		1,113
Note payable	2,347		2,347		3,112
Accrued interest payable	4,744		4,744		11,370
Other income/expense Related party interest expense	300	$ 516	1,093	$ 389
UBI IP [Member] \| Services Provided By Related Parties [Member]
Related Party Transaction [Line Items]
Prepaid expenses and other current assets	0		0		237
Amounts due from related parties	407		407		414
Amounts due to related parties	12,512		12,512		12,772
Current portion of note payable	929		929		1,113
Note payable	2,347		2,347		3,112
Accrued interest payable	0		0		$ 73
Research and development	67	0	424	1,139
General and administrative	1,076	0	2,133	0
Other income/expense Related party interest expense	$ 60	$ 0	$ 193	$ 0

Property and Equipment, Net (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Property, Plant and Equipment [Line Items]
Depreciation expense	$ 0.7	$ 0.4	$ 1.8	$ 1.1

Accrued Expenses and Other Current Liabilities	9 Months Ended
Accrued Expenses and Other Current Liabilities	Sep. 30, 2023
Accrued Expenses and Other Current Liabilities [Abstract]
Accrued Expenses and Other Current Liabilities	7. Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities consisted of the following (in thousands): September 30, December 31, 2023 2022 Accrued external research and development $ 1,720 $ 6,904 Accrued compensation 2,689 2,568 Accrued professional fees and other 334 1,722 Accrued interest — 176 $ 4,744 $ 11,370

Common Stock	9 Months Ended
Common Stock	Sep. 30, 2023
Common Stock [Abstract]
Common Stock	10. Common Stock The Company has reserved shares of Class A common stock for issuance for the following purposes: September 30, December 31, 2023 2022 Options and RSUs issued and outstanding 22,000,273 20,716,760 Options available for future grants 6,648,567 6,064,003 Warrants issued and outstanding 1,928,020 1,928,020 30,576,860 28,708,783

Short-Term Investments	9 Months Ended
Short-Term Investments	Sep. 30, 2023
Short-Term Investments [Abstract]
Short-Term Investments	4. Short-Term Investments The Company’s short-term investments consist of the following (in thousands): These securities mature in less than 1 year. As of September 30, 2023 Amortized Cost Unrealized Gains (Losses), Net Recorded Basis U.S. Treasury Securities $ 25,130 $ (6) $ 25,124 Total $ 25,130 $ (6) $ 25,124 As of December 31, 2022 Amortized Cost Unrealized Gains (Losses), Net Recorded Basis U.S. Treasury Securities $ 53,549 $ (197) $ 53,352 Total $ 53,549 $ (197) $ 53,352

Summary of Significant Accounting Policies (Policy)	9 Months Ended
Summary of Significant Accounting Policies (Policy)	Sep. 30, 2023
Summary of Significant Accounting Policies [Abstract]
Basis of Presentation	Basis of presentation The accompanying interim unaudited condensed consolidated financial statements have been prepared using generally accepted accounting principles in the United States of America (“GAAP”) and pursuant to the rules and regulations of the United States Securities and Exchange Commission (“SEC”) for interim financial reporting. These interim condensed consolidated financial statements are unaudited and, in the opinion of management, include all normal and recurring adjustments necessary to fairly present the results of the interim periods. The condensed consolidated balance sheet at December 31, 2022, has been derived from the audited financial statements at that date. Operating results for the three and nine months ended September 30, 2023 and cash flows for the nine months ended September 30, 2023 are not necessarily indicative of the results that may be expected for the fiscal year ending December 31, 2023 or any other future period. Certain information and note disclosures normally included in annual consolidated financial statements prepared in accordance with GAAP have been omitted in accordance with the rules and regulations for interim reporting of the SEC. These interim unaudited condensed financial statements should be read in conjunction with the consolidated financial statements and notes thereto included in our Annual Report on Form 10-K for the year ended December 31, 2022 filed with the SEC on March 27, 2023 (the “Annual Report”).
Recently Adopted Accounting Pronouncements and Recently Issued Accounting Pronouncements Not Yet Adopted	Recently adopted accounting pronouncements From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (“FASB”) or other standard setting bodies and are adopted by the Company as of the specified effective date. In June 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”). ASU 2016-13 significantly changes the impairment model for most financial assets and certain other instruments as it will require immediate recognition of estimated credit losses expected to occur over the remaining life of many financial assets, which will generally result in earlier recognition of allowances for credit losses on loans and other financial instruments. On January 1, 2023, the Company adopted ASU 2016-13. The adoption of this standard did not have a material impact on the Company's consolidated financial statements. Recently issued accounting pronouncements not yet adopted In August 2020, the FASB issued ASU 2020-06, Debt - Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging - Contracts in Entity's Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity's Own Equity, which is intended to simplify the accounting for certain financial instruments with characteristics of liabilities and equity, including convertible instruments and contracts on an entity's own equity. The guidance allows for either full retrospective adoption or modified retrospective adoption. The guidance is effective for the Company in the first quarter of fiscal year 2024 and early adoption is permitted. The Company is in the process of evaluating the effect the amendment will have on the consolidated financial statements.

Net Loss Per Share (Schedule of Excluded Potential Common Shares from Computation of Diluted Net Loss Per Share) (Details) - shares	3 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Excluded potential common shares from computation of diluted net loss per share	23,928,293	22,521,701
Options Issued And Outstanding [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Excluded potential common shares from computation of diluted net loss per share	21,800,273	20,293,681
Warrants Issued And Outstanding [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Excluded potential common shares from computation of diluted net loss per share	1,928,020	1,928,020
Restricted Stock Units Issued And Outstanding [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Excluded potential common shares from computation of diluted net loss per share	200,000	300,000

Prepaid Expenses and Other Current Assets (Narrative) (Details) - USD ($)	Sep. 30, 2023	Dec. 31, 2022
Prepaid Expenses and Other Current Assets [Line Items]
Clinical prepayments	$ 1,762,000	$ 2,679,000
Supplies	0	248,000
Unamortized portion of insurance fee	300,000	1,600,000
Clinical trials, UB-612 [Member]
Prepaid Expenses and Other Current Assets [Line Items]
Clinical prepayments	1,500,000
Related Party [Member]
Prepaid Expenses and Other Current Assets [Line Items]
Supplies	$ 0	$ 200,000

Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Class A Common Stock [Member]	Class B Common Stock [Member]	Common Stock [Member] Class A Common Stock [Member]	Common Stock [Member] Class B Common Stock [Member]	Additional Paid In Capital [Member]	Accumulated Other Comprehensive (Loss) [Member]	Accumulated Deficit [Member]
Beginning balance at Dec. 31, 2021	$ 128,619			$ 278	$ 1	$ 357,821		$ (229,481)
Beginning balance, common shares at Dec. 31, 2021				111,518,094	13,874,132
Issuance of common stock upon exercise of stock options, shares				448,998
Issuance of common stock upon exercise of stock options	121					121
Stock-based compensation expense	2,178					2,178
Net loss	(18,263)							(18,263)
Ending balance at Mar. 31, 2022	112,655			$ 278	$ 1	360,120		(247,744)
Ending balance, common shares at Mar. 31, 2022				111,967,092	13,874,132
Issuance of common stock upon exercise of stock options, shares				162,613
Issuance of common stock upon exercise of stock options	112					112
Stock-based compensation expense	1,826					1,826
Net loss	(17,252)							(17,252)
Ending balance at Jun. 30, 2022	97,341			$ 278	$ 1	362,058		(264,996)
Ending balance, common shares at Jun. 30, 2022				112,129,705	13,874,132
Issuance of common stock upon exercise of stock options, shares				52,165
Issuance of common stock upon exercise of stock options	29					29
Stock-based compensation expense	2,357					2,357
Net loss	(19,466)						$ (215)	(19,251)
Ending balance at Sep. 30, 2022	80,261			$ 278	$ 1	364,444	(215)	(284,247)
Ending balance, common shares at Sep. 30, 2022				112,871,792	13,874,132
Beginning balance at Dec. 31, 2022	62,177			$ 278	$ 1	366,798	(197)	(304,703)
Beginning balance, common shares at Dec. 31, 2022		112,182,750	13,874,132	112,182,750	13,874,132
Issuance of common stock upon exercise of stock options, shares				6,161
Issuance of common stock upon exercise of stock options	4					4
Stock-based compensation expense	2,225					2,225
Unrealized gain on investments	148						148
Net loss	(18,421)						0	(18,421)
Ending balance at Mar. 31, 2023	46,133			$ 278	$ 1	369,026	(49)	(323,124)
Ending balance, common shares at Mar. 31, 2023				112,188,911	13,874,132
Beginning balance at Dec. 31, 2022	$ 62,177			$ 278	$ 1	366,798	(197)	(304,703)
Beginning balance, common shares at Dec. 31, 2022		112,182,750	13,874,132	112,182,750	13,874,132
Issuance of common stock upon exercise of stock options, shares	689,042
Ending balance at Sep. 30, 2023	$ 23,705			$ 278	$ 1	373,678	(7)	(350,245)
Ending balance, common shares at Sep. 30, 2023		112,871,792	13,874,132	112,871,792	13,874,132
Beginning balance at Mar. 31, 2023	46,133			$ 278	$ 1	369,026	(49)	(323,124)
Beginning balance, common shares at Mar. 31, 2023				112,188,911	13,874,132
Issuance of common stock upon exercise of stock options, shares				635,001
Issuance of common stock upon exercise of stock options	393			$ 0		393
Stock-based compensation expense	2,433					2,433
Unrealized gain on investments	31						31
Net loss	(13,977)							(13,977)
Ending balance at Jun. 30, 2023	35,012			$ 278	$ 1	371,852	(18)	(337,101)
Ending balance, common shares at Jun. 30, 2023				112,823,912	13,874,132
Issuance of common stock upon exercise of stock options, shares				47,880
Issuance of common stock upon exercise of stock options	57					57
Stock-based compensation expense	1,769					1,769
Unrealized gain on investments	11						11
Net loss	(13,145)							(13,145)
Ending balance at Sep. 30, 2023	$ 23,705			$ 278	$ 1	$ 373,678	$ (7)	$ (350,245)
Ending balance, common shares at Sep. 30, 2023		112,871,792	13,874,132	112,871,792	13,874,132

- Definition

The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest.

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- Definition

Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.

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+ Details

Stock-Based Compensation (Tables)	9 Months Ended
Stock-Based Compensation (Tables)	Sep. 30, 2023
Stock-Based Compensation [Abstract]
Summary of Stock Option Activity	Number of Stock Options Outstanding Weighted Average Exercise Price Per Share Weighted Average Remaining Contractual Term (years) Aggregate Intrinsic Value (in thousands) Balance at December 31, 2022 20,416,760 $ 5.07 6.8 $ 7,166 Granted 3,466,782 2.28 Exercised (689,042) 0.66 Forfeited (1,394,227) 7.44 Balance at September 30, 2023 21,800,273 $ 4.62 6.2 $ 6,421 Options vested and exercisable at September 30, 2023 15,987,933 $ 4.50 5.9 $ 6,338
Summary of Restricted Stock Activity	Number of Shares Weighted Average Grant Date Fair Value Per Share Unvested at December 31, 2022 300,000 $ 3.76 Forfeited (100,000) $ 3.76 Unvested at September 30, 2023 200,000 $ 3.76
Schedule of Stock-Based Compensation Expense for Stock Options	Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 General and administrative $ 1,278 $ 1,509 $ 4,287 $ 3,888 Research and development 491 848 2,140 2,473 Total stock-based compensation expense $ 1,769 $ 2,357 $ 6,427 $ 6,361

Prepaid Expenses and Other Current Assets (Prepaid Expenses and Other Current Assets) (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Prepaid Expenses and Other Current Assets [Abstract]
Clinical prepayments	$ 1,762	$ 2,679
Prepaid insurance	280	1,870
Prepaid materials and supplies	0	248
Deposits	240	232
Other	942	522
Total	$ 3,224	$ 5,551

Notes payable (Remaining Principal Payments) (Details) - Notes Payable [Member] - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
2025 Note [Member]
Debt Instrument [Line Items]
2023 (remaining 3 months)	$ 113
2024	458
2025	9,553
Total	10,124	$ 10,455
2022 Promissory Note [Member]
Debt Instrument [Line Items]
2023 (remaining 3 months)	165
2024	1,029
2025	1,103
2026	979
Total	$ 3,276	$ 4,225

Summary of Significant Accounting Policies	9 Months Ended
Summary of Significant Accounting Policies	Sep. 30, 2023
Summary of Significant Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of presentation The accompanying interim unaudited condensed consolidated financial statements have been prepared using generally accepted accounting principles in the United States of America (“GAAP”) and pursuant to the rules and regulations of the United States Securities and Exchange Commission (“SEC”) for interim financial reporting. These interim condensed consolidated financial statements are unaudited and, in the opinion of management, include all normal and recurring adjustments necessary to fairly present the results of the interim periods. The condensed consolidated balance sheet at December 31, 2022, has been derived from the audited financial statements at that date. Operating results for the three and nine months ended September 30, 2023 and cash flows for the nine months ended September 30, 2023 are not necessarily indicative of the results that may be expected for the fiscal year ending December 31, 2023 or any other future period. Certain information and note disclosures normally included in annual consolidated financial statements prepared in accordance with GAAP have been omitted in accordance with the rules and regulations for interim reporting of the SEC. These interim unaudited condensed financial statements should be read in conjunction with the consolidated financial statements and notes thereto included in our Annual Report on Form 10-K for the year ended December 31, 2022 filed with the SEC on March 27, 2023 (the “Annual Report”). Significant accounting policies The significant accounting policies used in preparation of these unaudited condensed consolidated financial statements are disclosed in our annual consolidated financial statements for the year ended December 31, 2022 included in the Annual Report. There have been no changes to the Company’s significant accounting policies during the three and nine months ended September 30, 2023. Recently adopted accounting pronouncements From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (“FASB”) or other standard setting bodies and are adopted by the Company as of the specified effective date. In June 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”). ASU 2016-13 significantly changes the impairment model for most financial assets and certain other instruments as it will require immediate recognition of estimated credit losses expected to occur over the remaining life of many financial assets, which will generally result in earlier recognition of allowances for credit losses on loans and other financial instruments. On January 1, 2023, the Company adopted ASU 2016-13. The adoption of this standard did not have a material impact on the Company's consolidated financial statements. Recently issued accounting pronouncements not yet adopted In August 2020, the FASB issued ASU 2020-06, Debt - Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging - Contracts in Entity's Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity's Own Equity, which is intended to simplify the accounting for certain financial instruments with characteristics of liabilities and equity, including convertible instruments and contracts on an entity's own equity. The guidance allows for either full retrospective adoption or modified retrospective adoption. The guidance is effective for the Company in the first quarter of fiscal year 2024 and early adoption is permitted. The Company is in the process of evaluating the effect the amendment will have on the consolidated financial statements.

Income Taxes (Narrative) (Details)	3 Months Ended		9 Months Ended
Income Taxes (Narrative) (Details)	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023
Operating Loss Carryforwards [Line Items]
Effective Income Tax Rate Continuing Operations	0.00%	0.00%
Capital stock measurement period			3 years
Federal [Member]
Operating Loss Carryforwards [Line Items]
Stockholders owning directly or indirectly percentage of company stock	5.00%		5.00%
Federal [Member] \| Minimum [Member]
Operating Loss Carryforwards [Line Items]
Percentage of capital stock with change in ownership	50.00%		50.00%

Income Taxes	9 Months Ended
Income Taxes	Sep. 30, 2023
Income Taxes [Abstract]
Income Taxes	12. Income Taxes The Company computes its expected annual effective income tax rate in accordance with FASB Accounting Standards Codification (“ASC”) 740 , “Income Taxes” and makes changes on a quarterly basis, as necessary, based on certain factors such as changes in forecasted annual pre-tax income; changes to actual or forecasted permanent book to tax differences; impacts from tax audits with state, federal or foreign tax authorities; impacts from tax law changes; or change in judgment as to the realizability of deferred tax assets. The Company identifies items which are unusual and non-recurring in nature and treats these as discrete events. The tax effect of discrete items is recorded in the quarter in which the discrete events occur. The Company’s effective tax rate for the three months ended September 30, 2023 and September 30, 2022 was 0 %, due primarily to its uncertainty of realizing a benefit from net operating losses incurred during the period. In assessing the realizability of deferred tax assets, management considers whether it is more-likely-than-not that some or all of the recorded deferred tax assets will be realized. The ultimate realization of deferred tax assets is dependent on the generation of future taxable income in the periods in which those temporary differences become deductible. Management considers the scheduled reversal of deferred tax liabilities, projected future taxable income, and tax planning strategies in making this assessment. Based on these items and the consecutive years of pretax losses, management determined that enough uncertainty exists relative to the realization of the deferred income tax asset balances to warrant the application of a full valuation allowance for all taxing jurisdictions. The Company files income tax returns in the U.S. federal and various state and local jurisdictions. The Company also files returns in numerous foreign jurisdictions that have varied years remaining open for examination, but generally the statute of limitations is three to four years from when the return is filed. As of September 30, 2023, the Company has no ongoing audits. The Company has US net operating loss (“NOL”) carryforwards for federal and state income tax purposes. Use of the NOL carryforwards is limited under Section 382 of the Internal Revenue Code, as the Company had a change in ownership of more than 50 % of its capital stock over a three-year period as measured under Section 382 of the Internal Revenue Code of 1986, as amended (the “Code”). These complex changes of ownership rules generally focus on ownership changes involving stockholders owning directly or indirectly 5 % or more of our stock, including certain public “groups” of stockholders as set forth under Section 382 of the Code, including those arising from new stock issuances and other equity transactions. Some of these NOL carryforwards will expire if they are not used within certain periods. At this time, the Company considers it more likely than not that it will not have sufficient taxable income in the future that will allow us to realize these NOL carryforwards.

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

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Condensed Consolidated Statements of Operations and Other Comprehensive Loss (Income) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Operating expenses:
Research and development	$ 7,910	$ 12,468	$ 27,679	$ 34,609
General and administrative	5,535	7,300	18,956	20,546
Total operating expenses	13,445	19,768	46,635	55,155
Loss from operations	(13,445)	(19,768)	(46,635)	(55,155)
Other (income) expense:
Interest and other expense	176	54	514	264
Interest and other income	(512)	(545)	(1,657)	(625)
(Gain) loss on foreign currency transactions, net	36	(25)	50	(28)
Total other (income), net	(300)	(516)	(1,093)	(389)
Net loss	$ (13,145)	$ (19,252)	$ (45,542)	$ (54,766)
Net loss per share, basic	$ (0.10)	$ (0.15)	$ (0.36)	$ (0.43)
Net loss per share, diluted	$ (0.10)	$ (0.15)	$ (0.36)	$ (0.43)
Weighted average common shares outstanding, basic	126,736,784	126,036,865	126,272,546	125,899,557
Weighted average common shares outstanding, diluted	126,736,784	126,036,865	126,272,546	125,899,557
Other comprehensive (income) loss:
Unrealized (gain) loss on investments	$ (11)	$ 215	$ (190)	$ 215
Other comprehensive (income) loss	(11)	215	(190)	215
Comprehensive loss	$ (13,134)	$ (19,467)	$ (45,352)	$ (54,981)

Nature of the Business (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Nature of Business Disclosures [Line Items]
Cash and cash equivalents	$ 17,395	$ 18,875	$ 17,395	$ 18,875	$ 33,475
Net loss	(13,145)	$ (19,252)	(45,542)	(54,766)
Accumulated deficit	(350,245)		(350,245)		(304,703)
Net Cash Provided By Used In Operating Activities			(45,393)	$ (41,451)
Short Term Investments	$ 25,124		$ 25,124		$ 53,352

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8736-108599

Reference 31: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(5))
-URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442526-122756

Reference 32: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(iii)(B))
-URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442552-122756

Reference 33: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(iii)(A))
-URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442552-122756

Reference 34: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 30
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8906-108599

Reference 35: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8933-108599

+ Details

Other Long-Term Liabilities	9 Months Ended
Other Long-Term Liabilities	Sep. 30, 2023
Other Long-Term Liabilities [Abstract]
Other Long-Term Liabilities	8. Other Long-Term Liabilities Other long-term liabilities consisted of the following (in thousands): September 30, December 31, 2023 2022 Accrued taxes 236 236 $ 236 $ 236 As of September 30, 2023 and December 31, 2022, approximately $ 0.2 million of accrued taxes related to penalties and interest the Company may be subject to paying for late filing fees related to a foreign subsidiary. The Company expects these amounts to be forgiven but has accrued for them until the statute of limitations expires and it is appropriate to write them off.

Stock-Based Compensation	9 Months Ended
Stock-Based Compensation	Sep. 30, 2023
Stock-Based Compensation [Abstract]
Stock-Based Compensation	11. Stock-Based Compensation 2021 Omnibus Incentive Compensation Plan In November 2021, the Company established the 2021 Omnibus Incentive Compensation Plan (the “Plan”), which provides for the Company to grant nonqualified stock options, incentive (qualified) stock options, stock appreciation rights, restricted share awards, restricted stock units, performance awards, cash incentive awards and other equity-based awards (including fully vested shares). At inception in November 2021, the maximum number of shares of Class A common stock that could be issued under the Plan was 8,700,000 shares of Class A common stock. This number increases automatically on January 1 of each year, commencing January 1, 2023, by the number of shares equal to the lesser of (i) 4 % of the outstanding shares of our Class A common stock on the immediately preceding December 31, (ii) the number of shares determined by the compensation committee of the board of directors, if any such determination is made, and (iii) the number of shares underlying any awards granted during the preceding calendar year, net of the shares underlying awards canceled or forfeited under the Plan. On January 1, 2023, in accordance with the automatic “evergreen” provision of the Plan, the maximum number of shares that can be issued under the plan was increased to 11,886,306 . Stock Options As of September 30, 2023, there were options to purchase 15,437,818 shares of Class A stock outstanding and options to purchase 6,362,455 shares of Class B stock outstanding, of which options to purchase 10,948,474 shares of Class A common stock and options to purchase 5,039,459 shares of Class B common stock were exercisable, respectively. As of September 30, 2023, the maximum number of stock options awards available for future issuance under the Company’s plan is 6,648,567 . The following table summarizes stock option activity during the nine months ended September 30, 2023: The aggregate intrinsic value of options is calculated as the difference between the exercise price of the options and the fair value of the common stock for those options that had exercise prices lower than the fair value of the common stock as of September 30, 2023. The intrinsic value of options exercised during the nine months ended September 30, 2023 was $ 0.5 million. The weighted-average grant-date fair value per share of options granted during the nine months ended September 30, 2023 was $ 1.88 . Restricted Stock Units The following table summarizes the Company’s restricted stock unit activity for the nine months ended September 30, 2023: Stock-Based Compensation Expense The Company recorded stock-based compensation expense in the following expense categories in the accompanying unaudited condensed consolidated statements of operations and other comprehensive (income) loss (in thousands): As of September 30, 2023, total unrecognized compensation cost related to the unvested stock-based awards was $ 11.4 million, which is expected to be recognized over a weighted average period of 2.0 years. Number of Stock Options Outstanding Weighted Average Exercise Price Per Share Weighted Average Remaining Contractual Term (years) Aggregate Intrinsic Value (in thousands) Balance at December 31, 2022 20,416,760 $ 5.07 6.8 $ 7,166 Granted 3,466,782 2.28 Exercised (689,042) 0.66 Forfeited (1,394,227) 7.44 Balance at September 30, 2023 21,800,273 $ 4.62 6.2 $ 6,421 Options vested and exercisable at September 30, 2023 15,987,933 $ 4.50 5.9 $ 6,338 Number of Shares Weighted Average Grant Date Fair Value Per Share Unvested at December 31, 2022 300,000 $ 3.76 Forfeited (100,000) $ 3.76 Unvested at September 30, 2023 200,000 $ 3.76 Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 General and administrative $ 1,278 $ 1,509 $ 4,287 $ 3,888 Research and development 491 848 2,140 2,473 Total stock-based compensation expense $ 1,769 $ 2,357 $ 6,427 $ 6,361

Notes payable (Tables)	9 Months Ended
Notes payable (Tables)	Sep. 30, 2023
Note, 2025 [Member]
Debt Instrument [Line Items]
Carrying Value	September 30, December 31, 2023 2022 Principal $ 10,124 $ 10,455 Unamortized debt issuance cost (92) (131) Carrying amount 10,032 10,324 Less: current portion (402) (391) Note payable, net of current portion and debt issuance cost $ 9,630 $ 9,933
Remaining Principal Payments	Amount 2023 (remaining 3 months) $ 113 2024 458 2025 9,553 $ 10,124
2022 Promissory Note [Member]
Debt Instrument [Line Items]
Carrying Value	September 30, December 31, 2023 2022 Principal $ 3,276 $ 4,225 Less: current portion (929) (1,113) Note payable with related party, net of current portion $ 2,347 $ 3,112
Remaining Principal Payments	Amount 2023 (remaining 3 months) $ 165 2024 1,029 2025 1,103 2026 979 $ 3,276

Short-Term Investments (Tables)	9 Months Ended
Short-Term Investments (Tables)	Sep. 30, 2023
Short-Term Investments [Abstract]
Schedule of Short-Term Investments	As of September 30, 2023 Amortized Cost Unrealized Gains (Losses), Net Recorded Basis U.S. Treasury Securities $ 25,130 $ (6) $ 25,124 Total $ 25,130 $ (6) $ 25,124 As of December 31, 2022 Amortized Cost Unrealized Gains (Losses), Net Recorded Basis U.S. Treasury Securities $ 53,549 $ (197) $ 53,352 Total $ 53,549 $ (197) $ 53,352

Stock-Based Compensation (Summary of Restricted Stock Activity) (Details)	9 Months Ended
	Sep. 30, 2023 $ / shares shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares, Issued \| shares	3,466,782
Weighted-average grant-date fair value per share, Issued \| $ / shares	$ 1.88
Restricted Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unvested, Number of Shares, Beginning Balance \| shares	300,000
Forfeited, Number of Shares \| shares	(100,000)
Unvested, Number of Shares, Ending Balance \| shares	200,000
Unvested, Weighted average grant date fair value per share, beginning balance \| $ / shares	$ 3.76
Forfeited, weighted average grant date fair value per share \| $ / shares	3.76
Unvested, Weighted average grant date fair value per share, ending balance \| $ / shares	$ 3.76

Accrued Expenses and Other Current Liabilities (Accrued Expenses and Other Current Liabilities) (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Accrued Expenses and Other Current Liabilities [Abstract]
Accrued external research and development	$ 1,720	$ 6,904
Accrued compensation	2,689	2,568
Accrued professional fees and other	334	1,722
Accrued interest	0	176
Total	$ 4,744	$ 11,370

Fair Value Measurements (Schedule of Financial Instruments Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	$ 25,124	$ 53,352
Assets	36,049	81,076
Money Market Account [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	10,925	27,724
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	25,124	53,352
Assets	36,049	81,076
Level 1 [Member] \| Money Market Account [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	10,925	27,724
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	0	0
Assets	0	0
Level 2 [Member] \| Money Market Account [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	0	0
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	0	0
Assets	0	0
Level 3 [Member] \| Money Market Account [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	$ 0	$ 0

Stock-Based Compensation (Summary of Stock Option Activity) (Details) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2023 USD ($) $ / shares shares	Dec. 31, 2022 USD ($) $ / shares shares
Stock-Based Compensation [Abstract]
Number of stock options outstanding, Beginning balance \| shares	20,416,760
Number of stock options outstanding, Granted \| shares	3,466,782
Number of stock options outstanding, Exercised \| shares	(689,042)
Number of stock options outstanding, Forfeited \| shares	(1,394,227)
Number of stock options outstanding, Ending balance \| shares	21,800,273	20,416,760
Number of stock options outstanding, Vested and exercisable \| shares	15,987,933
Weighted average exercise price per share, Beginning balance \| $ / shares	$ 5.07
Weighted average exercise price per share, Granted \| $ / shares	2.28
Weighted average exercise price per share, Exercised \| $ / shares	0.66
Weighted average exercise price per share, Forfeited \| $ / shares	7.44
Weighted average exercise price per share, Ending balance \| $ / shares	4.62	$ 5.07
Weighted average exercise price per share, Vested and exercisable \| $ / shares	$ 4.50
Weighted average remaining contractual term (years)	6 years 2 months 12 days	6 years 9 months 18 days
Weighted average remaining contractual term, Vested and exercisable	5 years 10 months 24 days
Aggregate intrinsic value, Beginning balance \| $	$ 7,166
Aggregate intrinsic value, Ending balance \| $	6,421	$ 7,166
Aggregate intrinsic value, Vested and exercisable \| $	$ 6,338

Prepaid Expenses and Other Current Assets (Tables)	9 Months Ended
Prepaid Expenses and Other Current Assets (Tables)	Sep. 30, 2023
Prepaid Expenses and Other Current Assets [Abstract]
Prepaid Expenses and Other Current Assets	September 30, December 31, 2023 2022 Clinical prepayments $ 1,762 $ 2,679 Prepaid insurance 280 1,870 Prepaid materials and supplies — 248 Deposits 240 232 Other 942 522 $ 3,224 $ 5,551

Common Stock (Reserved Share of Common Stock for Issuance) (Details) - shares	Sep. 30, 2023	Dec. 31, 2022
Class Of Stock [Line Items]
Options issued and outstanding	21,800,273	20,416,760
Options [Member]
Class Of Stock [Line Items]
Options issued and outstanding	22,000,273	20,716,760
Options available for future grants	6,648,567	6,064,003
Warrants issued and outstanding	1,928,020	1,928,020
Reserved Shares of Common Stock	30,576,860	28,708,783

Other Long-Term Liabilities (Tables)	9 Months Ended
Other Long-Term Liabilities (Tables)	Sep. 30, 2023
Other Long-Term Liabilities [Abstract]
Other Liabilities	September 30, December 31, 2023 2022 Accrued taxes 236 236 $ 236 $ 236

Net Loss Per Share (Tables)	9 Months Ended
Net Loss Per Share (Tables)	Sep. 30, 2023
Net Loss Per Share [Abstract]
Schedule of Excluded Potential Common Shares from Computation of Diluted Net Loss Per Share	September 30, 2023 2022 Options issued and outstanding 21,800,273 20,293,681 Warrants issued and outstanding 1,928,020 1,928,020 Restricted stock units issued and outstanding 200,000 300,000 23,928,293 22,521,701

Property and Equipment, Net (Tables)	9 Months Ended
Property and Equipment, Net (Tables)	Sep. 30, 2023
Property and Equipment, Net [Abstract]
Property and Equipment, Net	September 30, December 31, 2023 2022 Airplane $ 11,983 $ 11,983 Laboratory and computer equipment 3,310 3,146 Software 426 415 Leasehold improvements 534 403 Facilities, furniture and fixtures 98 37 Vehicles 87 87 Construction in progress 86 65 Total property and equipment 16,524 16,136 Less: accumulated depreciation and amortization (5,401) (3,624) Property and equipment, net $ 11,123 $ 12,512

Related Party Transactions	9 Months Ended
Related Party Transactions	Sep. 30, 2023
Related Party Transactions [Abstract]
Related Party Transactions	16. Related Party Transactions The Company has related party arrangements with UBI and a number of its affiliated companies namely, United Biomedical, Inc., Asia (“UBIA”), UBI Pharma, Inc. (“UBI-P”), United BioPharma, Inc (“UBP”) and UBI IP Holding (“UBI-IP”). As of September 30, 2023, UBI owned 44 % of the Company’s stock. The majority of the voting interests in both UBI and the Company were held by a group of immediate family members, and as such the entities are under common control. These related parties are governed by various Master Services Agreements (“MSA”) detailed below. UBI MSA - UBI provides research, development and clinical functions to the Company. There is also a purchase arrangement with UBI for the production and shipment of the Company’s diagnostic test kits. UBIA MSA - UBI-Asia for manufacturing, quality control, testing, validation, and supply services. UBP MSA - UBP provides the Company with manufacturing, testing and validation services. COVID MSA (“COVID MSA”) - COVID MSA provides that UBI acts as COVAXX’s agent with respect to matters relating the Company’s COVID-19 program and provides research, development, manufacturing and back office administrative services to the Company. COVID-19 Relief MSA - A four-company MSA with UBI, UBI-Asia and UBP. The Company is an exclusive licensee of technologies related to diagnostics, vaccines, and therapies for COVID-19. The MSA established the terms under which UBI- Asia provides research, development, testing and manufacturing services to the Company and UBP provides contract development and manufacturing services to the Company. In August 2021, Vaxxinity entered into a license agreement with UBI and certain of its affiliates (collectively, the “Licensors”) that expanded intellectual property rights previously licensed under the Original UBI Licenses in exchange for a warrant to purchase 1,928,020 shares of Vaxxinity Class A common stock. The UBI Warrant is exercisable at an exercise price of $ 12.45 per share (subject to adjustment pursuant thereto),is not subject to vesting, and has a term of five years . See note 14 to the condensed consolidated financial statements. The Company also considers Destination Systems, its travel and logistics firm, a related party since its Chief Executive Officer, Landon Ogilvie, is on the Company’s board of directors. Total related party operating activity is as follows (in thousands): September 30, December 31, 2023 2022 Consolidated balance sheet Assets Prepaid expenses and other current assets $ — $ 237 Amounts due from related parties 407 414 Liabilities Amounts due to related parties 12,512 12,772 Current portion of note payable 929 1,113 Note payable 2,347 3,112 Accrued interest payable — 73 Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Operating expenses Research and development Services provided by related parties $ 67 $ — $ 424 $ 1,139 General and administrative Services provided by related parties $ 1,076 $ — $ 2,133 $ — Other income/expense Related party interest expense $ 60 $ — $ 193 $ —

Fair Value Measurements (Tables)	9 Months Ended
Fair Value Measurements (Tables)	Sep. 30, 2023
Fair Value Measurements [Abstract]
Schedule of Financial Instruments Measured at Fair Value on a Recurring Basis	September 30, 2023 Level 1 Level 2 Level 3 Total Assets: Short-term investments $ 25,124 $ — $ — $ 25,124 Money market accounts 10,925 — — 10,925 Total assets $ 36,049 $ — $ — $ 36,049 December 31, 2022 Level 1 Level 2 Level 3 Total Assets: Short-term investments $ 53,352 $ — $ — $ 53,352 Money market account 27,724 — — 27,724 Total assets $ 81,076 $ — $ — $ 81,076

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Cash flows from operating activities:
Net loss	$ (45,542)	$ (54,766)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation expense	1,778	1,144
Amortization of debt issuance costs	39	40
Amortization of discount on short-term investments	(1,222)	(422)
Stock-based compensation expense	6,427	6,361
Changes in operating assets and liabilities:
Amounts due from related parties	7	(7)
Prepaid expenses and other current assets	2,327	3,349
Long-term deposits	0	(2,076)
Accounts payable	(2,321)	127
Amounts due to related parties	(260)	(2,731)
Accrued expenses and other current liabilities	(6,626)	7,530
Net cash used in operating activities	(45,393)	(41,451)
Cash flows from investing activities:
Purchase of short-term investments	(43,587)	(107,526)
Proceeds from maturity of short-term investments	73,227	27,500
Purchases of property and equipment	(389)	(1,574)
Net cash provided by (used in) investing activities	29,251	(81,600)
Cash flows from financing activities:
Repayments of note payable	(331)	(320)
Repayments of note payable with related party	(949)	0
Proceeds from exercise of stock options	453	262
Net cash used in financing activities	(827)	(58)
Change in cash, cash equivalents and restricted cash	(16,969)	(123,109)
Cash, cash equivalents and restricted cash at beginning of period	34,570	145,057
Cash, cash equivalents and restricted cash at end of period	17,601	21,948
Reconciliation of cash, cash equivalents and restricted cash:
Cash, cash equivalents and restricted cash at end of period	17,601	21,948
Less restricted cash	(206)	(3,073)
Cash and cash equivalents end of period	17,395	18,875
Supplemental Disclosure
Cash paid for interest	$ 592	$ 277

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2023	Dec. 31, 2022
Class A Common Stock [Member]
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	1,000,000,000	1,000,000,000
Common stock, shares issued	112,871,792	112,182,750
Common stock, shares outstanding	112,871,792	112,182,750
Class B Common Stock [Member]
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	13,874,132	13,874,132
Common stock, shares outstanding	13,874,132	13,874,132

Net Loss Per Share	9 Months Ended
Net Loss Per Share	Sep. 30, 2023
Net Loss Per Share [Abstract]
Net Loss Per Share	13. Net Loss Per Share The Company’s potentially dilutive securities, which include warrants, options and restricted stock units, have been excluded from the computation of diluted net loss per share as the effect would be to reduce the net loss per share. Therefore, the weighted average number of common shares outstanding used to calculate both basic and diluted net loss per share is the same. The Company excluded the following potential common shares, presented based on amounts outstanding at each period end, from the computation of diluted net loss per share for the three months ended September 30, 2023 and 2022 because including them would have had an anti-dilutive effect: September 30, 2023 2022 Options issued and outstanding 21,800,273 20,293,681 Warrants issued and outstanding 1,928,020 1,928,020 Restricted stock units issued and outstanding 200,000 300,000 23,928,293 22,521,701

Notes Payable	9 Months Ended
Notes Payable	Sep. 30, 2023
Notes Payable [Abstract]
Notes Payable	9. Notes Payable Note Payable—Airplane In connection with the acquisition of an airplane, the Company entered into a note payable agreement (the “2025 Note”) in June 2020 for $ 11.5 million, with an annual interest rate of 3.4 % and a maturity date of June 9, 2025 . Principal and interest payments are payable monthly in the amount of $ 0.1 million with a final payment of $ 9.4 million at maturity. The 2025 Note is guaranteed by the co-founders of the Company. In addition, the Company incurred debt issuance costs of $ 0.3 million, which are being amortized over the term of the loan. There are no financial covenants associated with the 2025 Note. The carrying value of the 2025 Note is as follows (in thousands): As of September 30, 2023, the remaining principal payments for the 2025 Note are as follows (in thousands): Interest expense associated with the 2025 Note was $ 0.1 million and $ 0.3 million for the three and nine months ended September 30, 2023, respectively. Interest expense associated with the 2025 Note was $ 0.1 million and $ 0.3 million for the three and nine months ended September 30, 2022, respectively. Accrued interest of less than $ 0.1 million was included in accrued expenses and other current liabilities in the accompanying condensed consolidated balance sheets as of September 30, 2023 and December 31, 2022. Promissory Note with Related Party In October 2022, the Company entered into a related party unsecured promissory note (the “2022 Promissory Note”) with UBI for $ 4.2 million. The 2022 Promissory Note accrues interest at 7.0 % per annum and is due October 1, 2026 . The 2022 Promissory Note was issued to satisfy accounts payable to UBI totaling $ 4.2 million. The carrying value of the 2022 Promissory Note is as follows (in thousands): As of September 30, 2023, the remaining principal payments for the 2022 Promissory Note are as follows (in thousands): Interest expense associated with the 2022 Promissory Note was $ 0.1 million and $ 0.2 million for the three and nine months ended September 30, 2023, respectively. September 30, December 31, 2023 2022 Principal $ 10,124 $ 10,455 Unamortized debt issuance cost (92) (131) Carrying amount 10,032 10,324 Less: current portion (402) (391) Note payable, net of current portion and debt issuance cost $ 9,630 $ 9,933 Amount 2023 (remaining 3 months) $ 113 2024 458 2025 9,553 $ 10,124 September 30, December 31, 2023 2022 Principal $ 3,276 $ 4,225 Less: current portion (929) (1,113) Note payable with related party, net of current portion $ 2,347 $ 3,112 Amount 2023 (remaining 3 months) $ 165 2024 1,029 2025 1,103 2026 979 $ 3,276

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 17,395	$ 33,475
Short-term investments	25,124	53,352
Restricted cash	206	1,095
Amounts due from related parties	407	414
Prepaid expenses and other current assets	3,224	5,551
Total current assets	46,356	93,887
Property and equipment, net	11,123	12,512
Total assets	57,479	106,399
Current liabilities:
Accounts payable	2,974	5,295
Amounts due to related parties	12,512	12,772
Accrued expenses and other current liabilities	4,744	11,370
Note payable, net of debt issuance cost	402	391
Note payable to related party	929	1,113
Total current liabilities	21,561	30,941
Other liabilities:
Note payable, net of debt issuance cost, net of current portion	9,630	9,933
Note payable to related party, net of current portion	2,347	3,112
Other long-term liabilities	236	236
Total liabilities	33,774	44,222
Commitments and contingencies (Note 14)
Stockholders' equity:
Additional paid-in capital	373,678	366,798
Accumulated other comprehensive loss	(7)	(197)
Accumulated deficit	(350,245)	(304,703)
Total stockholders' equity	23,705	62,177
Total liabilities and stockholders' equity	57,479	106,399
Class A Common Stock [Member]
Stockholders' equity:
Common stock:	278	278
Class B Common Stock [Member]
Stockholders' equity:
Common stock:	$ 1	$ 1

Stock-Based Compensation (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions		9 Months Ended
	Jan. 01, 2023	Sep. 30, 2023	Dec. 31, 2022	Nov. 30, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options outstanding		21,800,273	20,416,760
Options exercisable		15,987,933
Weighted-average grant-date fair value per share, Issued		$ 1.88
Total unrecognized compensation cost		$ 11.4
Recognized over a weighted average period		2 years
Options [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares available for grant		6,648,567	6,064,003
Options outstanding		22,000,273	20,716,760
Intrinsic value of options exercised		$ 0.5
Class A Common Stock [Member] \| Options [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options outstanding		15,437,818
Options exercisable		10,948,474
Common Class B [Member] \| Options [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options outstanding		6,362,455
Options exercisable		5,039,459
2021 Plan [Member] \| Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Increase in shares available for grant	11,886,306
2021 Plan [Member] \| Class A Common Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Available for issuance under Plan				8,700,000
Percentage increase in shares available for grant				4.00%

Commitments and Contingencies (Narrative) (Details)		1 Months Ended		3 Months Ended			9 Months Ended
Commitments and Contingencies (Narrative) (Details)	Nov. 03, 2021 USD ($)	Apr. 30, 2022 USD ($) ft²	Aug. 31, 2021 USD ($)	Sep. 30, 2023 USD ($) Item	Dec. 31, 2022 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) Item	Sep. 30, 2022 USD ($)	Aug. 09, 2023 USD ($)	Aug. 31, 2022 USD ($) ft²	Apr. 30, 2021 USD ($)
Commitments And Contingencies [Line Items]
Rent expense				$ 100,000		$ 200,000	$ 500,000	$ 400,000
Materials Expensed					$ 0
Number Of Operating Lease Agreements \| Item				2			2
New York Lease [Member]
Commitments And Contingencies [Line Items]
Lease in square feet \| ft²		4,419
Lease, initial term		1 year
Florida Lease [Member]
Commitments And Contingencies [Line Items]
Security deposit										$ 100,000
Lease in square feet \| ft²										9,839
Lease, initial term										1 year
Lease obligation										$ 500,000
Indemnification Agreement [Member]
Commitments And Contingencies [Line Items]
Purchase obligation				$ 0	$ 0		$ 0
Expected Claim [Member] \| Maximum [Member]
Commitments And Contingencies [Line Items]
Potential loss									$ 4,200,000
Expected Claim [Member] \| Minimum [Member]
Commitments And Contingencies [Line Items]
Potential loss									$ 0
Contract Research Organizations [Member]
Commitments And Contingencies [Line Items]
Remaining prepayments				1,500,000			1,500,000
Contract Manufacturing Organizations [Member]
Commitments And Contingencies [Line Items]
Remaining prepayments				0			0
UB-612 [Member]
Commitments And Contingencies [Line Items]
Materials Ordered			$ 7,200,000
Materials Expensed							3,000,000.0
Materials Received			3,000,000.0
Amount Of Material Canceled			$ 4,200,000
Purchase obligation											$ 3,000,000
Michael J. Fox Foundation Grant [Member]
Commitments And Contingencies [Line Items]
Project Grant	$ 800,000
Grant, Accrued Liability, Current				0			0
Reduction In Research And Development							0	$ 0
Coalition for Epidemic Preparedness Innovations ("CEPI") Grant [Member]
Commitments And Contingencies [Line Items]
Project Grant		$ 9,300,000
Restricted Cash And Current Accrued Liability				$ 0			0
Reduction In Research And Development							$ 1,800,000

Notes payable (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
Notes payable (Narrative) (Details) - USD ($) $ in Millions	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022	Oct. 31, 2022	Jun. 30, 2020
2025 Note [Member]
Debt Instrument [Line Items]
Notes Payable, Related Parties							$ 11.5
Debt Instrument Interest Rate Stated Percentage							3.40%
Debt maturity date							Jun. 09, 2025
Interest Expense, Debt	$ 0.1	$ 0.1	$ 0.3	$ 0.3
Debt Instrument Periodic Payment Interest			0.1
Debt Instrument Periodic Payment Terms Balloon Payment To Be Paid	9.4		9.4
Payments Of Debt Issuance Costs			0.3
2025 Note [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt Instrument Increase Accrued Interest			0.1		$ 0.1
2022 Promissory Note [Member]
Debt Instrument [Line Items]
Debt Instrument Interest Rate Stated Percentage						7.00%
Debt maturity date						Oct. 01, 2026
2022 Promissory Note [Member] \| Related Party [Member]
Debt Instrument [Line Items]
Notes Payable, Related Parties						$ 4.2
Accounts payable						$ 4.2
Interest Expense, Debt	$ 0.1		$ 0.2

Property and Equipment, Net	9 Months Ended
Property and Equipment, Net	Sep. 30, 2023
Property and Equipment, Net [Abstract]
Property and Equipment, Net	6. Property and Equipment, Net Property and equipment, net consisted of the following (in thousands): September 30, December 31, 2023 2022 Airplane $ 11,983 $ 11,983 Laboratory and computer equipment 3,310 3,146 Software 426 415 Leasehold improvements 534 403 Facilities, furniture and fixtures 98 37 Vehicles 87 87 Construction in progress 86 65 Total property and equipment 16,524 16,136 Less: accumulated depreciation and amortization (5,401) (3,624) Property and equipment, net $ 11,123 $ 12,512 Depreciation expense for the three and nine months ended September 30, 2023 was $ 0.7 million and $ 1.8 million, respectively. Depreciation expense for the three and nine months ended September 30, 2022 was $ 0.4 million and $ 1.1 million, respectively.

Fair Value Measurements	9 Months Ended
Fair Value Measurements	Sep. 30, 2023
Fair Value Measurements [Abstract]
Fair Value Measurements	3. Fair Value Measurements The Company's money market accounts and short-term investments are shown at fair value based on unadjusted quoted market prices in active markets for identical assets. The following table presents information about the Company’s financial instruments measured at fair value on a recurring basis and indicate the level of the fair value hierarchy used to determine such fair values (in thousands): During the three and nine months ended September 30, 2023 and the year ended December 31, 2022, there were no transfers between Level 1, Level 2 and Level 3. September 30, 2023 Level 1 Level 2 Level 3 Total Assets: Short-term investments $ 25,124 $ — $ — $ 25,124 Money market accounts 10,925 — — 10,925 Total assets $ 36,049 $ — $ — $ 36,049 December 31, 2022 Level 1 Level 2 Level 3 Total Assets: Short-term investments $ 53,352 $ — $ — $ 53,352 Money market account 27,724 — — 27,724 Total assets $ 81,076 $ — $ — $ 81,076

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Benefit Plans	9 Months Ended
Benefit Plans	Sep. 30, 2023
Benefit Plans [Abstract]
Benefit Plans	15. Benefit Plans In March 2018, the Company established a defined contribution savings plan under Section 401(k) of the Code. This plan covers substantially all U.S. employees who meet minimum age and service requirements and allows participants to defer a portion of their annual compensation on a pre-tax basis. The Company matches employee contributions to the Plan at 100 % up to 4 % of the employee’s base salary. The Company offers its Ireland-based employees a Personal Retirement Savings Account (“PRSA”) that allows participants to defer a portion of their annual compensation. The Company provides contributions equal to 5 % of each participant’s annual salary. During the three and nine months ended September 30, 2023 and 2022, the Company contributed less than $ 0.1 million to PRSA accounts.

Other Long-Term Liabilities (Narrative) (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Other Long-Term Liabilities [Abstract]
Income Tax Examination Penalties And Interest Accrued	$ 0.2	$ 0.2

Notes payable (Carrying Value) (Details) - Notes Payable [Member] - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
2025 Note [Member]
Debt Instrument [Line Items]
Principal	$ 10,124	$ 10,455
Unamortized debt issuance cost	(92)	(131)
Total	10,032	10,324
Less: current portion	(402)	(391)
Note payable, net of current portion and debt issuance cost	9,630	9,933
2022 Promissory Note [Member]
Debt Instrument [Line Items]
Principal	3,276	4,225
Less: current portion	(929)	(1,113)
Note payable, net of current portion and debt issuance cost	$ 2,347	$ 3,112

- Definition

Amount, excluding unamortized premium (discount) and debt issuance cost, of long-term debt. Excludes lease obligation.

+ References + Details

Nature of the Business	9 Months Ended
Nature of the Business	Sep. 30, 2023
Nature of the Business [Abstract]
Nature of the Business	1. Nature of the Business Vaxxinity, Inc., a Delaware corporation (“Vaxxinity ,” and together with its subsidiaries, the “Company”), was formed through the combination of two separate businesses that originated from United Biomedical, Inc. (“UBI”) in two separate transactions: a spin-out from UBI in 2014 of operations focused on developing chronic disease product candidates that resulted in United Neuroscience (“UNS”), and a second spin-out from UBI in 2020 of operations focused on the development of a COVID-19 vaccine that resulted in C19 Corp. (“COVAXX”). On February 2, 2021, Vaxxinity was incorporated for the purpose of reorganizing and combining UNS and COVAXX and on March 2, 2021, did so by acquiring all of the outstanding equity interests of UNS and COVAXX pursuant to a contribution and exchange agreement (the “Contribution and Exchange Agreement”) whereby the existing equity holders of UNS and COVAXX contributed their equity interests in each of UNS and COVAXX in exchange for equity in Vaxxinity (the “Reorganization”). On December 31, 2022, COVAXX merged with and into Vaxxinity. The Company is a biotechnology company currently focused on developing product candidates for human use in the fields of neurology, pain, cardiovascular diseases and coronaviruses utilizing its “Vaxxine Platform”—a synthetic peptide vaccine technology first developed by UBI and subsequently refined over the last two decades. The Company is engaged in the development of rationally designed prophylactic and therapeutic vaccines to combat common chronic diseases with large global unmet medical need. The Company is also developing a heterologous booster vaccine for SARS-Cov-2. UBI is a significant shareholder of the Company and, therefore, considered a related party. The Company is subject to risks and uncertainties common to early-stage companies in the biotechnology industry including, but not limited to, uncertainty of product development and commercialization, lack of marketing and sales history, development by its competitors of new technological innovations, dependence on key personnel, market acceptance of products, product liability, protection of proprietary technology, ability to raise additional financing, and compliance with global government regulations. If the Company does not successfully commercialize or out-license any of its product candidates, it will be unable to generate recurring product revenue or achieve profitability. The Company’s product candidates are in development and will require significant additional research and development efforts, including extensive pre-clinical and clinical testing and regulatory approval prior to commercialization. These efforts require significant amounts of additional capital, adequate personnel and infrastructure and extensive compliance-reporting capabilities. There can be no assurance that the Company’s research and development will be successfully completed, that adequate protection for the Company’s intellectual property will be obtained, that any products developed will obtain necessary government regulatory approval or that any approved products will be commercially viable. Even if the Company’s product development efforts are successful, it is uncertain when, if ever, the Company will generate significant revenue from product sales. The Company operates in an environment of rapid change in technology and is dependent upon the services of its employees and consultants. Liquidity and Going Concern Assessment As of September 30, 2023, the Company had $ 17.4 million of cash and cash equivalents and $ 25.1 million of short-term investments to fund operations. To date, the Company has primarily financed its operations through the sale of convertible preferred stock and common stock, borrowings under promissory notes (including convertible notes), a portion of which has been raised from related party entities, and grants from foundations such as the Coalition for Epidemic Preparedness Innovations (CEPI) and the Michael J. Fox Foundation (MJFF). The Company has experienced significant negative cash flows from operations since inception, and incurred a net loss of $ 45.5 million for the nine months ended September 30, 2023. Net cash used in operating activities for the nine months ended September 30, 2023 was $ 45.4 million. In addition, as of September 30, 2023, the Company has an accumulated deficit of $ 350.2 million. The Company expects to incur substantial operating losses and negative cash flows from operations for the foreseeable future. In accordance with ASC 205-40, Presentation of Financial Statements-Going Concern, management is required to evaluate whether there are conditions or events, considered in the aggregate, that raise substantial doubt about the Company's ability to continue as a going concern within one year after the date that the financial statements are issued. When management identifies conditions or events, considered in the aggregate, that raise substantial doubt about the Company's ability to continue as a going concern, management must consider whether its plans to mitigate those relevant conditions or events will alleviate the substantial doubt. Given that the Company has incurred substantial operating losses and negative cash flows from operations since inception and expects to continue to incur substantial operating losses and negative cash flows from operations for the foreseeable future, management assessed that there are conditions or events, considered in the aggregate, as of the issue date of these financial statements, which raise substantial doubt about the Company's ability to continue as a going concern. Management considered whether its plans to mitigate those relevant conditions or events will alleviate the substantial doubt about the Company's ability to continue as a going concern. These plans include raising new capital through public or private equity offerings, strategic collaborations, debt financing and other capital sources or combinations thereof, and as needed cost reduction through attrition, organization restructuring, and curtailment of certain research and development activities. However, there are significant risks and uncertainties as to whether these plans will be achieved or additional funding will be available on terms acceptable to the Company, or at all. Due to the risks and uncertainties, management cannot conclude that substantial doubt about the Company's ability to continue as a going concern has been alleviated. As such, there is substantial doubt about the entity's ability to continue as a going concern within one year after the date that the financial statements are issued. However, since liquidation is not imminent, the accompanying unaudited condensed consolidated financial statements have been prepared assuming that the Company will continue as a going concern, which contemplates the realization of assets and satisfaction of liabilities in the ordinary course of business. The unaudited condensed consolidated financial statements do not include any adjustments relating to the recoverability and classification of recorded asset amounts or the amounts and classification of liabilities that might result from the outcome of the uncertainties described above.

Common Stock (Tables)	9 Months Ended
Common Stock (Tables)	Sep. 30, 2023
Common Stock [Abstract]
Reserved Shares of Common Stock for Issuance	September 30, December 31, 2023 2022 Options and RSUs issued and outstanding 22,000,273 20,716,760 Options available for future grants 6,648,567 6,064,003 Warrants issued and outstanding 1,928,020 1,928,020 30,576,860 28,708,783

Related Party Transactions (Narrative) (Details) - UBI [Member] - $ / shares	1 Months Ended
	Aug. 31, 2021	Sep. 30, 2023
Related Party Transaction [Line Items]
Warrants granted	1,928,020
Warrants, exercise price	$ 12.45
Warrant, contractual term	5 years
UBI1 [Member]
Related Party Transaction [Line Items]
Percent of ownership		44.00%

Commitments and Contingencies	9 Months Ended
Commitments and Contingencies	Sep. 30, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	14. Commitments and Contingencies Contractual Obligations The Company enters into agreements with CROs to conduct clinical trials and preclinical studies and CMOs to produce vaccines and other potential product candidates. Contracts with CROs and CMOs are generally cancellable, with notice, at the Company’s option. As of September 30, 2023, the Company had remaining prepayments to CROs of $ 1.5 million and no remaining prepayments to CMOs for activities associated with the conduct of its clinical trials and for the production of the Company’s anticipated vaccine product candidate. Michael J. Fox Foundation Grant On November 3, 2021, the Company was awarded a grant from the Michael J. Fox Foundation for Parkinson’s Research (“MJFF”) in the amount of $ 0.8 million to be used in a project for the exploration of markers for target engagement in individuals immunized with UB-312, an active a -Synuclein (“aSyn”) immunotherapy. The Company will oversee sample management, sample preparation (IgG fractions) and distribution, as well as characterize the binding properties of the antibodies against pathological forms of aSyn. As funding is expected to be received in tranches over a two-year period, and the amounts received in each tranche are expected to be utilized within 12 months, the funds received are recognized as a short-term accrued liability. The Company recognizes payments from MJFF as a reduction of research and development expenses, in the same period as the expenses that the grant is intended to reimburse are incurred. As of September 30, 2023, there was no balance remaining in the accrued liability related to this grant. For the nine months ended September 30, 2023 and 2022, the Company did no t recognize any reduction of research and development expenses for amounts reimbursed through the grant. Coalition for Epidemic Preparedness Innovations (“CEPI”) Grant In April 2022, the Company entered into an agreement with the Coalition for Epidemic Preparedness Innovations (“CEPI”) whereby CEPI agreed to provide funding of up to $ 9.3 million to co-fund a Phase 3 clinical trial of the Company’s next generation UB-612 COVID-19 vaccine candidate as a heterologous – or ‘mix-and-match’ – booster dose. The Phase 3 trial, which began in early 2022, is evaluating the ability of UB-612 to boost COVID-19 immunity against the original strain and multiple variants of concern including Omicron - in people aged 16 years or older, who have been previously immunized with an authorized COVID-19 vaccine. The Company will also be performing further manufacturing scale-up work to enable readiness for potential commercialization. Under the terms of the agreement with CEPI, if successful, a portion of the released doses of the commercial product will be delivered to the COVID-19 Vaccines Global Access (“COVAX”) consortium for distribution to developing countries at low cost. Cash payments received in advance under the CEPI Funding Agreement are restricted as to their use until expenditures contemplated in the funding agreement are incurred. As funding is expected to be received in tranches over an 18-month period, and the amounts received in each tranche are expected to be utilized within 12 months, the funds received are reflected within restricted cash with a corresponding short-term accrued liability. As of September 30, 2023, the Company had no remaining restricted cash or accrued liability related to CEPI funding. The Company recognizes payments from CEPI as a reduction of research and development expenses, in the same period as the expenses that the grant is intended to reimburse are incurred. For the nine months ended September 30, 2023, the Company reduced research and development expenses by $ 1.8 million for amounts reimbursed through the grant. Lease Agreements The Company has two operating lease agreements for office and laboratory space. The Company is also required to pay certain operating costs under its leases. In August 2023, the Company entered into a lease for 9,839 square feet of lab and office space with Space Florida in Exploration Park, Florida commencing August 12, 2023. The lease has an initial one-year term with an annual lease obligation of $ 0.5 million, after lessee credits. Additionally, the lease requires the Company to provide a security deposit in the amount of less than $ 0.1 million. In April 2022, the Company entered into a facility lease agreement for 4,419 square feet of office space in New York, New York. The lease commenced in April 2022 and will expire in March 2029 with no option to renew. This lease and its terms were reviewed using the guidance found in ASC 842, “Leases”. Since the lease has a non-cancellable period of one year , and after the first year both the Company and the landlord have the option to early terminate the lease for any or no reason, the Company has elected to apply the short- term expedient, which does not subject the New York lease to capitalization. Rent expense for the three and nine months ended September 30, 2023 was $ 0.1 million and $ 0.5 million, respectively. Rent expense for the three and nine months ended September 30, 2022 was $ 0.2 million and $ 0.4 million, respectively. License Agreements In August 2021, the Company entered into a license agreement (the “Platform License Agreement”) with UBI and certain of its affiliates that expanded intellectual property rights held under previously issued license agreements with UBI. As part of the agreement, the Company obtained a worldwide, sublicensable (subject to certain conditions), perpetual, fully paid-up, royalty-free license to research, develop, make, have made, utilize, import, export, market, distribute, offer for sale, sell, have sold, commercialize or otherwise exploit peptide-based vaccines in the field of all human prophylactic and therapeutic uses, except for such vaccines related to human immunodeficiency virus (HIV), herpes simplex virus (HSE) and Immunoglobulin E (IgE). The patents and patent applications licensed under the Platform License Agreement include claims directed to a CpG delivery system, artificial T helper cell epitopes and certain designer peptides and proteins utilized in UB-612. In consideration for the Platform License Agreement, the Company issued to UBI a warrant to purchase Class A common stock (the “UBI Warrant”). The Company considered ASC 805, “Business Combinations” (“ASC 805”) and ASC 730, “Research and Development” (“ASC 730”) in determining how to account for the license agreement acquired and the issuance of the UBI Warrant. The majority of the voting interests in UBI and in the Company were held by a group of immediate family members, at the time of the transaction, and as such the transaction constitutes a common control transaction, which requires the license to be accounted for at the carrying value in the books of the transferor and the excess of consideration paid over the carrying value as a capital transaction. Indemnification Agreements In the ordinary course of business, the Company may provide indemnification of varying scope and terms to employees, consultants, vendors, lessors, business partners and other parties with respect to certain matters including, but not limited to, losses arising out of breach of such agreements or from intellectual property infringement claims made by third parties. In addition, the Company has entered into indemnification agreements with members of its board of directors and executive officers that will require the Company to, among other things, indemnify them against certain liabilities that may arise by reason of their status or service as directors or officers. The maximum potential amount of future payments the Company could be required to make under these indemnification agreements is, in many cases, unlimited. To date, the Company has not incurred any material costs as a result of such indemnification obligations. The Company is not aware of any indemnification arrangements that could have a material effect on its financial position, results of operations, or cash flows, and it has no t accrued any liabilities related to such obligations as of September 30, 2023 and December 31, 2022. Legal Proceedings From time to time, the Company may become involved in legal proceedings arising in the ordinary course of business. As of September 30, 2023 and December 31, 2022, the Company was not a party to any material legal matters or claims. Loss Contingency In April 2021, the Company engaged United Biopharma, Inc. (“UBP”) to begin acquiring raw materials for use in the production of GMP grade recombinant protein for UB-612, the Company’s COVID-19 vaccine candidate under an Authorization to Proceed (“ATP”) agreement for $ 3 million of materials. Through August 2021, $ 7.2 million of materials were ordered by UBP, $ 3.0 million of materials were received by UBP and paid for with an advance payment from the Company. The Company has recognized $ 3.0 million in expense for these materials purchases authorized under the ATP. When the Company asked to pause further manufacture of protein upon rejection of the Emergency Use Authorization application by Taiwan in August 2021, UBP requested that its suppliers cancel the remaining $ 4.2 million in orders for which it had not taken possession of the materials. In the fourth quarter of 2022, the Company learned that most of the suppliers refused to cancel the orders, although some agreed to seek other buyers for the materials. For these orders, management has not yet concluded that a loss for the Company is probable, or that one amount of loss is a better estimate than any other amount, since they were not originally authorized by the ATP and UBP’s suppliers may be able to dispose of some amount to other buyers. Hence, an expense has no t been recognized for them. As of November 8, 2023, there is no claim against the Company by UBP related to these orders, no settlement or other agreement has been reached between the Company and UBP or, to the Company’s knowledge, between UBP and its suppliers. Therefore, the range of the potential loss is still $ 0 to $ 4.2 million.

Benefit Plans (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
Benefit Plans (Narrative) (Details) - USD ($) $ in Millions	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Defined Contribution Plan Disclosure [Line Items]
Company matches employee contributions to the Plan at 100% up to 4%			100.00%
Maximum percentage of employee's base salary employer matches 100%			4.00%
Foreign Plan [Member]
Defined Contribution Plan Disclosure [Line Items]
Company matches employee contributions to the Plan at 100% up to 4%			5.00%
Foreign Plan [Member] \| Personal Retirement Savings Account [Member]
Defined Contribution Plan Disclosure [Line Items]
Company contributions	$ 0.1	$ 0.1	$ 0.1	$ 0.1

Short-Term Investments (Schedule of Short-Term Investments) (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Cash And Cash Equivalents [Line Items]
Amortized Cost	$ 25,130	$ 53,549
Unrealized Gains (Losses), Net	(6)	(197)
Recorded Basis	25,124	53,352
U S Treasury Securities [Member]
Cash And Cash Equivalents [Line Items]
Amortized Cost	25,130	53,549
Unrealized Gains (Losses), Net	(6)	(197)
Recorded Basis	$ 25,124	$ 53,352

Fair Value Measurements (Narrative) (Details) - USD ($)	3 Months Ended	9 Months Ended	12 Months Ended
Fair Value Measurements (Narrative) (Details) - USD ($)	Sep. 30, 2023	Sep. 30, 2023	Dec. 31, 2022
Class Of Warrant Or Right [Line Items]
Transfers between fair value hierarchies assets liabilities	$ 0	$ 0	$ 0

Stock-Based Compensation (Schedule of Stock-Based Compensation Expense for Stock Options) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation expense	$ 1,769	$ 2,357	$ 6,427	$ 6,361
Research And Development [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation expense	491	848	2,140	2,473
General And Administrative [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation expense	$ 1,278	$ 1,509	$ 4,287	$ 3,888

Related Party Transactions (Tables)	9 Months Ended
Related Party Transactions (Tables)	Sep. 30, 2023
Related Party Transactions [Abstract]
Schedule of Related Party Operating Activity	September 30, December 31, 2023 2022 Consolidated balance sheet Assets Prepaid expenses and other current assets $ — $ 237 Amounts due from related parties 407 414 Liabilities Amounts due to related parties 12,512 12,772 Current portion of note payable 929 1,113 Note payable 2,347 3,112 Accrued interest payable — 73 Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Operating expenses Research and development Services provided by related parties $ 67 $ — $ 424 $ 1,139 General and administrative Services provided by related parties $ 1,076 $ — $ 2,133 $ — Other income/expense Related party interest expense $ 60 $ — $ 193 $ —

Other Long-Term Liabilities (Other Liabilities) (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Other Long-Term Liabilities [Abstract]
Accrued taxes	$ 236	$ 236
Total	$ 236	$ 236