Exhibit 10.1

Execution Version

SECOND AMENDMENT TO LOAN AND SECURITY AGREEMENT

THIS SECOND AMENDMENT to Loan and Security Agreement (this “Amendment”) is entered into as of February 13, 2018 (the “Amendment Date”), by and among OXFORD FINANCE LLC, a Delaware limited liability company with an office located at 133 North Fairfax Street, Alexandria, Virginia 22314 (in its individual capacity, “Oxford”; and in its capacity as Collateral Agent, “Collateral Agent”), the Lenders listed on Schedule 1.1 to the Loan Agreement (as defined below) from time to time including Oxford in its capacity as a Lender (each a “Lender” and collectively, the “Lenders”), VAXART, INC., a Delaware corporation with offices located at 290 Utah Ave., Suite 200, South San Francisco, CA 94080, (which will change its name to “VAXART BIOSCIENCES, INC.” effective immediately prior to the Closing Date pursuant to the Merger Agreement (as each term is defined below)(“Existing Borrower”), AVIRAGEN THERAPEUTICS, INC., a Delaware corporation with offices located at 2500 Northwinds Parkway, Suite 100, Alpharetta, GA 30009, (which will change its name to “VAXART, INC.” effective on the Closing Date pursuant to the Merger Agreement (as each term is defined below) (“Aviragen”), BIOTA HOLDINGS LIMITED, an Australian limited company and wholly owned Subsidiary of Aviragen with offices located at Unit 10 585 Blackburn Road, Notting Hill VIC 3168 Australia (“Biota Holdings”) and BIOTA SCIENTIFIC MANAGEMENT PTY LTD., an Australian proprietary limited company and wholly owned Subsidiary of Biota Holdings with offices located at Unit 10 585 Blackburn Road, Notting Hill VIC 3168 Australia (“Biota Scientific”). Each of Aviragen, Biota Holdings and Biota Scientific may be referred to herein, individually as “New Borrower” and collectively as “New Borrowers.” On and after the Amendment Date, each of Existing Borrower, Aviragen, Biota Holdings and Biota Scientific, may be referred to herein, individually and collectively, jointly and severally, as “Borrower.”

WHEREAS, Collateral Agent, Existing Borrower and the Lenders have entered into that certain Loan and Security Agreement, dated as of December 22, 2016 (as amended, supplemented or otherwise modified from time to time, the “Loan Agreement”), pursuant to which the Lenders have provided to Borrower certain loans in accordance with the terms and conditions thereof;

WHEREAS, Existing Borrower, Aviragen, and AGORA MERGER SUB, INC., a Delaware corporation entered into that certain that certain Agreement and Plan of Merger (the “Merger Agreement”), dated as of October 27, 2017, pursuant to which, among other things, Existing Borrower became a wholly owned subsidiary of Aviragen;

WHEREAS, Required Lenders and Collateral Agent consented to the Existing Borrower entering into the Merger Agreement contingent upon, among other things, (i) the Existing Borrower entering into this Amendment, and (ii) the New Borrowers joining the Loan Agreement, and other Loan Documents, as Borrowers, and entering into this Amendment, on the date hereof;

WHEREAS, Borrower, Lenders and Collateral Agent desire to amend certain provisions of the Loan Agreement as provided herein and subject to the terms and conditions set forth herein; and

NOW, THEREFORE, in consideration of the promises, covenants and agreements contained herein, and other good and valuable consideration, the receipt and adequacy of which are hereby acknowledged, Borrower, Lenders and Collateral Agent hereby agree as follows:

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7.6 Maintenance of Collateral Accounts. (i) Maintain any Collateral Account except pursuant to the terms of Section 6.6 hereof, and (ii) the aggregate balance at any time of all Collateral Accounts of the Borrower’s Subsidiaries that are neither co-Borrowers or secured guarantors, including without limitation Anaconda Pharma SAS and Biota Europe Limited, shall not exceed One Hundred Fifty Thousand Dollars ($150,000.00) for each of Anaconda Pharma SAS and Biota Europe Limited.

7.7 Distributions; Investments. (a) Pay any dividends (other than dividends payable solely in capital stock or dividends paid from a Subsidiary to a Borrower) or make any distribution or payment in respect of or redeem, retire or purchase any capital stock (other than repurchases pursuant to the terms of employee stock purchase plans, employee restricted stock agreements, stockholder rights plans, director or consultant stock option plans, or similar plans, provided such repurchases do not exceed Two Hundred Thousand Dollars ($200,000.00) in the aggregate per fiscal year) or (b) directly or indirectly make any Investment other than Permitted Investments, or permit any of its Subsidiaries to do so; provided, that the aggregate amount of all Investments in each of Anaconda Pharma SAS and Biota Europe Limited do not exceed One Hundred Fifty Thousand Dollars ($150,000.00) in any fiscal year.

7.12 Certain Subsidiaries’ Asset Levels. Cause the assets (including without limitation, cash and Cash Equivalents) of (i) Anaconda Pharma SAS to exceed $200,000 in any fiscal year, or (ii) Biota Europe Limited to exceed $200,000 in any fiscal year.

8.12 Delisting. The shares of common stock of Aviragen are delisted from NASDAQ Capital Market because of failure to comply with continued listing standards thereof or due to a voluntary delisting which results in such shares not being listed on any other nationally recognized stock exchange in the United States having listing standards at least as restrictive as the NASDAQ Capital Market.

12.12 Borrower Liability. Any Borrower may, acting singly, request Credit Extensions hereunder. Each Borrower hereby appoints the other as agent for the other for all purposes hereunder, including with respect to requesting Credit Extensions hereunder. Each Borrower hereunder shall be jointly and severally obligated to repay all Credit Extensions made hereunder, regardless of which Borrower actually receives said Credit Extension, as if each Borrower hereunder directly received all Credit Extensions. Each Borrower waives (a) any suretyship defenses available to it under the Code or any other applicable law, and (b) any right to require Collateral Agent or any Lender to: (i) proceed against any Borrower or any other person; (ii) proceed against or exhaust any security; or (iii) pursue any other remedy. Collateral Agent and or any Lender may exercise or not exercise any right or remedy it has against any Borrower or any security it holds (including the right to foreclose by judicial or non judicial sale) without affecting any Borrower’s liability. Notwithstanding any other provision of this Agreement or other related document, each Borrower irrevocably waives all rights that it may have at law or in equity (including, without limitation, any law subrogating Borrower to the rights of Collateral Agent and the Lenders under this Agreement) to seek contribution, indemnification or any other form of reimbursement from any other Borrower, or any other Person now or hereafter primarily or secondarily liable for any of the Obligations, for any payment made by Borrower with respect to the Obligations in connection with this Agreement or otherwise and all rights that it might have to benefit from, or to participate in, any security for the Obligations as a result of any

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payment made by Borrower with respect to the Obligations in connection with this Agreement or otherwise. Any agreement providing for indemnification, reimbursement or any other arrangement prohibited under this Section shall be null and void. If any payment is made to a Borrower in contravention of this Section, such Borrower shall hold such payment in trust for Collateral Agent and the Lenders and such payment shall be promptly delivered to Collateral Agent for application to the Obligations, whether matured or unmatured.

“Anaconda Pharma SAS” is an entity organized under the laws of France and wholly owned Subsidiary of Aviragen.

“Aviragen” is AVIRAGEN THERAPEUTICS, INC., a Delaware corporation, provided that following the Closing Date of the Merger Agreement, AVIRAGEN THERAPEUTICS, INC.’s name shall be changed to “VAXART, INC.,” a Delaware corporation.

“Biota Europe Limited” is an entity organized under the laws of the United Kingdom and wholly owned Subsidiary of Biota Holdings.

“Biota Holdings” is BIOTA HOLDINGS LIMITED, an Australian limited company.

“Biota Scientific” is BIOTA SCIENTIFIC MANAGEMENT PTY LTD., an Australian proprietary limited company.

“Existing Borrower” is VAXART, INC., a Delaware corporation, provided that following the Closing Date of the Merger Agreement, VAXART, INC.’s name shall be changed to “VAXART BIOSCIENCES, INC.,” a Delaware corporation.

“New Borrower” is each of Aviragen, Biota Holdings and Biota Scientific.

“Borrower” is individually and collectively, jointly and severally, New Borrower and the Existing Borrower.

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reflect the pledge of the Shares of the Existing Borrower. Upon the occurrence and during the continuance of an Event of Default under the Loan Agreement, Collateral Agent may effect the transfer of any securities included in the Collateral (including but not limited to the Shares of Existing Borrower) into the name of Collateral Agent and cause new (as applicable) certificates representing such securities to be issued in the name of Collateral Agent or its transferee. Each of Aviragen and Existing Borrower will execute and deliver such documents, and take or cause to be taken such actions, as Collateral Agent may reasonably request to perfect or continue the perfection of Collateral Agent’s security interest in the Shares of Existing Borrower. Unless an Event of Default shall have occurred and be continuing, Aviragen shall be entitled to exercise any voting rights with respect to the Shares of Existing Borrower and to give consents, waivers and ratifications in respect thereof, provided that no vote shall be cast or consent, waiver or ratification given or action taken which would be inconsistent with any of the terms of the Loan Agreement or which would constitute or create any violation of any of such terms. All such rights to vote and give consents, waivers and ratifications shall terminate upon the occurrence and continuance of an Event of Default under the Loan Agreement. For the avoidance of doubt, Lender and Borrowers hereby acknowledge and agree that the Borrower shall not be required to pledge more than 65% of the stock of Anaconda Pharma SAS and Biota Europe Limited.

Borrower shall deliver to Collateral Agent (a) a landlord’s consent executed in favor of Collateral Agent in respect of all of each New Borrower’s leased locations, in such form and substance as are acceptable to Collateral Agent where any New Borrower maintains Collateral having a book value in excess of Three Hundred Thousand Dollars ($300,000.00) and/or where its books and records are located; and (b) a bailee waiver executed in favor of Collateral Agent in respect of each third party bailee where any New Borrower maintains Collateral having a book value in excess of Three Hundred Thousand Dollars ($300,000.00), in such form and substance as are reasonably acceptable to Collateral Agent.

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Each Borrower shall deliver executed Control Agreements with respect to all Collateral Accounts located in the United States maintained by each Borrower, including without limitation each New Borrower.

Each Borrower shall deliver executed original Control Agreements with respect to all Collateral Accounts located outside of the United States maintained by Borrower; provided that, in such jurisdictions where it may or may not be customary for banks to enter into account control agreements with lenders Collateral Agent shall exercise its discretion with respect to the foregoing requirements concerning such jurisdictions.

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IN WITNESS WHEREOF, the parties hereto have caused this Second Amendment to Loan and Security Agreement to be executed as of the date first set forth above.

Exhibit A

Form of Amended and Restated Secured Promissory Note (Term A Loan)

[see attached]

AMENDED AND RESTATED

SECURED PROMISSORY NOTE

(Term A Loan)

FOR VALUE RECEIVED, each of the undersigned, VAXART, INC., a Delaware corporation with offices located at 385 Oyster Point Blvd., Suite 9A, South San Francisco, CA 94080 (“Existing Borrower”), AVIRAGEN THERAPEUTICS, INC., a Delaware corporation with offices located at 2500 Northwinds Parkway, Suite 100, Alpharetta, GA 30009, BIOTA HOLDINGS LIMITED, an Australian limited company with offices located at Unit 10 585 Blackburn Road, Notting Hill VIC 3168 Australia, and BIOTA SCIENTIFIC MANAGEMENT PTY LTD., an Australian proprietary limited company with offices located at Unit 10 585 Blackburn Road, Notting Hill VIC 3168 Australia (each of the foregoing are, individually, collectively, jointly and severally “Borrower”) HEREBY PROMISES TO PAY to the order of OXFORD FINANCE LLC (“Lender”) the principal amount of FOUR MILLION EIGHT HUNDRED SIXTY ONE THOUSAND ONE HUNDRED ELEVEN DOLLARS AND 11/100 ($4,861,111.11), plus interest on the aggregate unpaid principal amount of such Term A Loan, at the rates and in accordance with the terms of the Loan and Security Agreement dated December 22, 2016 by and among Borrower, Lender, Oxford Finance LLC, as Collateral Agent, and the other Lenders from time to time party thereto (as amended, restated, supplemented or otherwise modified from time to time, the “Loan Agreement”). If not sooner paid, the entire principal amount and all accrued and unpaid interest hereunder shall be due and payable on the Maturity Date as set forth in the Loan Agreement. Any capitalized term not otherwise defined herein shall have the meaning attributed to such term in the Loan Agreement.

Principal, interest and all other amounts due with respect to the Term A Loan, are payable in lawful money of the United States of America to Lender as set forth in the Loan Agreement and this Amended and Restated Secured Promissory Note (Term Loan A) (this “Note”). The principal amount of this Note and the interest rate applicable thereto, and all payments made with respect thereto, shall be recorded by Lender and, prior to any transfer hereof, endorsed on the grid attached hereto which is part of this Note. The Loan Agreement, among other things, (a) provides for the making of a secured Term A Loan by Lender to Borrower, and (b) contains provisions for acceleration of the maturity hereof upon the happening of certain stated events.

This Note may not be prepaid except as set forth in Section 2.2 (c) or Section 2.2(d) of the Loan Agreement. This Note and the obligation of Borrower to repay the unpaid principal amount of the Term A Loan, interest on the Term A Loan and all other amounts due Lender under the Loan Agreement is secured under the terms of the Loan Agreement. Presentment for payment, demand, notice of protest and all other demands and notices of any kind in connection with the execution, delivery, performance and enforcement of this Note are hereby waived. Borrower shall pay all reasonable fees and expenses, including, without limitation, reasonable attorneys’ fees and costs, incurred by Lender in the enforcement or attempt to enforce any of Borrower’s obligations hereunder not performed when due.

This Note is an amendment and restatement of, but not issued in satisfaction of, that certain Secured Promissory Note (Term A Loan) dated December 22, 2016, made by Existing Borrower to the order of the Lender in the principal sum of $5,000,000 (as amended, restated or otherwise modified, the “Original Note”). This Note is delivered in substitution of the Original Note, and upon proper execution and delivery hereof, the Original Note shall be deemed null and void.

This Note shall be governed by, and construed and interpreted in accordance with, the internal laws of the State of California. The ownership of an interest in this Note shall be registered on a record of ownership maintained by Lender or its agent. Notwithstanding anything else in this Note to the contrary, the right to the principal of, and stated interest on, this Note may be transferred only if the transfer is registered on such record of ownership and the transferee is identified as the owner of an interest in the obligation. Borrower shall be entitled to treat the registered holder of this Note (as recorded on such record of ownership) as the owner in fact thereof for all purposes and shall not be bound to recognize any equitable or other claim to or interest in this Note on the part of any other person or entity.

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IN WITNESS WHEREOF, Borrower has caused this Note to be duly executed by one of its officers thereunto duly authorized on the date hereof.

[Signature Page to Amended and Restated Secured Promissory Note (Term A Loan)]

LOAN INTEREST RATE AND PAYMENTS OF PRINCIPAL

EXHIBIT B

Form of Disbursement Letter

[see attached]

DISBURSEMENT LETTER

[DATE]

The undersigned, being the duly elected and acting                      of VAXART, INC. (formerly known as, AVIRAGEN THERAPEUTICS, INC.), a Delaware corporation with office located at 2500 Northwinds Parkway, Suite 100, Alpharetta, GA 30009, on behalf of itself and each other Borrower under the Loan Agreement (as defined below) (individually and collectively, jointly and severally, “Borrower”), does hereby certify to OXFORD FINANCE LLC (“Oxford” and “Lender”), as collateral agent (the “Collateral Agent”) in connection with that certain Loan and Security Agreement dated as of December 22, 2016, by and among Borrower, Collateral Agent and the Lenders from time to time party thereto (as amended, restated, supplemented or otherwise modified from time to time, the “Loan Agreement”; with other capitalized terms used below having the meanings ascribed thereto in the Loan Agreement) that:

1. The representations and warranties made by Borrower in Section 5 of the Loan Agreement and in the other Loan Documents are true and correct in all material respects as of the date hereof.

2. No event or condition has occurred that would constitute an Event of Default under the Loan Agreement or any other Loan Document.

3. Borrower is in compliance with the covenants and requirements contained in Sections 4, 6 and 7 of the Loan Agreement.

4. All conditions referred to in Section 3 of the Loan Agreement to the making of the Loan to be made on or about the date hereof have been satisfied or waived by Collateral Agent.

5. No Material Adverse Change has occurred.

6. The undersigned is a Responsible Officer.

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8. The proceeds of the Term [A][B] Loan shall be disbursed as follows:

9. The [Term A Loan][Term B Loan] shall amortize in accordance with the Amortization Table attached hereto.

10. The aggregate net proceeds of the Term Loans shall be transferred to the Designated Deposit Account as follows:

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Dated as of the date first set forth above.

[Signature Page to Disbursement Letter]

AMORTIZATION TABLE

(Term [A][B] Loan)

[see attached]

EXHIBIT C

Compliance Certificate

The undersigned authorized officer (“Officer”) of VAXART, INC., hereby certifies for itself on behalf of all Borrowers under the Loan Agreement (as defined herein) that in accordance with the terms and conditions of the Loan and Security Agreement by and among Borrower, Collateral Agent, and the Lenders from time to time party thereto (as amended, restated, supplemented or otherwise modified from time to time, the “Loan Agreement;” capitalized terms used but not otherwise defined herein shall have the meanings given them in the Loan Agreement),

(a) Borrower is in complete compliance for the period ending                      with all required covenants in the Loan Agreement, except as noted below;

(b) There are no Events of Default, except as noted below;

(c) Except as noted below, all representations and warranties of Borrower stated in the Loan Documents are true and correct in all material respects on this date and for the period described in (a), above; provided, however, that such materiality qualifier shall not be applicable to any representations and warranties that already are qualified or modified by materiality in the text thereof; and provided, further that those representations and warranties expressly referring to a specific date shall be true, accurate and complete in all material respects as of such date.

(d) Borrower, and each of Borrower’s Subsidiaries, has timely filed all required tax returns and reports, or extensions therefore, and Borrower, and each of Borrower’s Subsidiaries, has timely paid all foreign, federal, state, and local taxes, assessments, deposits and contributions owed by Borrower, or Subsidiary, except as otherwise permitted pursuant to the terms of Section 5.8 of the Loan Agreement;

(e) No Liens have been levied or claims made against Borrower or any of its Subsidiaries relating to unpaid employee payroll or benefits of which Borrower has not previously provided written notification to Collateral Agent and the Lenders.

Attached are the required documents, if any, supporting our certification(s). The Officer, on behalf of Borrower, further certifies that the attached financial statements are prepared in accordance with Generally Accepted Accounting Principles (GAAP) and are consistently applied from one period to the next except as explained in an accompanying letter or footnotes and except, in the case of unaudited financial statements, for the absence of footnotes and subject to year-end audit adjustments as to the interim financial statements.

Please indicate compliance status since the last Compliance Certificate by circling Yes, No, or N/A under “Complies” column.

Deposit and Securities Accounts

(Please list all accounts; attach separate sheet if additional space needed)

Other Matters

Exceptions

Please explain any exceptions with respect to the certification above: (If no exceptions exist, state “No exceptions.” Attach separate sheet if additional space needed.)