2

VAXART, INC.

Unaudited Pro Forma Condensed Combined Balance Sheet

December 31, 2017

(In thousands)

See notes to unaudited pro forma condensed combined financial information.

3

VAXART, INC.

Unaudited Pro Forma Condensed Combined Statement of Operations

Year Ended December 31, 2017

(In thousands, except share and per share amounts)

4

VAXART, INC.

Notes to Unaudited Pro Forma Condensed Combined Financial Information

December 31, 2017

(1)     Description of the Transaction and Basis of Presentation

Description of Transaction

On February 13, 2018, Aviragen Therapeutics, Inc. (“Aviragen”) merged with and into pre-merger Vaxart, Inc. (“Private Vaxart”), with Private Vaxart becoming a wholly-owned subsidiary of Aviragen and the surviving corporation following the completion of the merger in accordance with the Agreement and Plan of Merger and Reorganization (the “Merger Agreement”) with Aviragen. At the closing of the merger, all of Private Vaxart’s convertible promissory notes and preferred stock, including dividends earned but not paid, converted into shares of Private Vaxart’s common stock. Each outstanding share of Private Vaxart’s common stock then converted into the right to receive approximately 0.22148 shares of common stock of Aviragen (the “Conversion Ratio”). Immediately following the effective time of the merger, Aviragen equity holders owned approximately 49% of the outstanding capital stock of the combined company on a fully diluted basis, with Private Vaxart security holders owning approximately 51% of the combined company (the “Combined Company”). Immediately following the merger, Private Vaxart changed its name to Vaxart Biosciences, Inc. and Aviragen changed its name to Vaxart, Inc.

The Combined Company also assumed all of the stock options outstanding under the Vaxart 2007 Stock Option Plan (the “Vaxart Plan”), with such stock options representing the right to purchase a number of shares of Combined Company common stock equal to approximately 0.22148 multiplied by the number of shares of Private Vaxart’s common stock previously represented by such options under the Vaxart Plan.

Also on February 13, 2018, in connection with, and immediately following the completion of, the Merger, the Combined Company effected a reverse stock split at a ratio of one new share for every eleven shares of its common stock outstanding (the “1:11 Reverse Stock Split”). All outstanding stock options and warrants of the Combined Company were adjusted commensurately. No fractional shares were issued in connection with the 1:11 Reverse Stock Split. Stockholders who were otherwise entitled to receive a fractional share of common stock received cash on a pro-rated basis. The 1:11 Reverse Stock Split did not change the number of shares of common or preferred stock that the Company is authorized to issue, or the par value of the Company’s common or preferred stock.

Immediately after the Merger there were approximately 7.1 million post-reverse stock split shares of the Combined Company’s common stock outstanding. Following the closing of the Merger, the business conducted by the Combined Company became primarily the business that was being conducted by Private Vaxart, a clinical-stage company focused on developing oral recombinant protein vaccines based on its proprietary oral vaccine platform.

Basis of Presentation

The unaudited pro forma condensed combined financial statements were prepared in accordance with the regulations of the Securities and Exchange Commission (“SEC”). The unaudited pro forma condensed combined balance sheet as of December 31, 2017, is presented as if the merger had been completed on December 31, 2017. The unaudited pro forma condensed combined statement of operations for the year ended December 31, 2017, combines the audited historical statement of operations of Private Vaxart for its fiscal year ended December 31, 2017, with information from which Aviragen’s audited consolidated statement of operations for its fiscal year ended June 30, 2017, adjusted by adding its unaudited condensed consolidated statements of operations for the six months ended December 31, 2017, and subtracting its unaudited condensed consolidated statements of operations for the six months ended December 31, 2016, was derived, and gives pro forma effect to the merger as if it had been completed on January 1, 2017.

5

VAXART, INC.

Notes to Unaudited Pro Forma Condensed Combined Financial Information

December 31, 2017

Based on the terms of the merger, Private Vaxart is deemed to be the acquiring company for accounting purposes and the transaction will be accounted for as a business combination in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”). Accordingly, the assets and liabilities of Private Vaxart will be recorded as of the Merger closing date at their respective carrying value and the acquired net assets of Aviragen will be recorded as of the Merger closing date at their fair value. For the purpose of these unaudited pro forma condensed combined financial statements, management of Private Vaxart and Aviragen have determined a preliminary estimated purchase price for the asset acquisition, and such amount has been calculated as described in Note 2 to these unaudited pro forma condensed combined financial statements. The net assets acquired in connection with the transaction are at their estimated fair values. A final determination of these estimated fair values will be based on the actual net acquired assets of Aviragen as of the Merger closing date. The pro forma adjustments are preliminary and based on the estimated fair value of the net assets acquired and have been prepared to illustrate the estimated effect of the asset acquisition. Because Private Vaxart primarily acquired financial assets, Private Vaxart’s transaction costs will be expensed as incurred. To the extent there are significant changes to the Combined Company’s business following completion of the Merger, the assumptions and estimates set forth in the unaudited pro forma condensed combined financial statements could change significantly. Accordingly, the purchase price adjustments recorded in these unaudited pro forma condensed combined financial statements are subject to further adjustment as additional information becomes available and as additional analyses are conducted following the completion of the Merger. There can be no assurances that these additional analyses will not result in material changes to the estimates of fair value.

(2)     Preliminary Purchase Price Allocation

The estimated preliminary purchase price, which represents the consideration transferred to Aviragen securityholders in the reverse transaction, is calculated based on the number of shares of common stock of the Combined Company that Aviragen securityholders will own as of the closing of the transaction. On December 31, 2017, Aviragen had 38,649,237 shares of common stock outstanding and a market capitalization of approximately $21,887,000. This market capitalization was based on the expectation that Aviragen shareholders would receive 40% of the Combined Company, so the estimated market capitalization of the Combined Company would have been approximately $54,718,000. When the merger was consummated on February 13, 2018, Aviragen’s shareholders received approximately 49% of the Combined Company. Thus, the preliminary purchase price is estimated to be 49% of the Combined Company’s estimated market capitalization on December 31, 2017, or $26,812,000. The estimated preliminary purchase price at the merger closing date has changed due to changes in Aviragen’s stock price occurring between December 31, 2017, and the completion of the merger on February 13, 2018.

The allocation of the total preliminary estimated purchase price to the acquired assets and assumed liabilities of Aviragen, based on the estimated fair values as of December 31, 2017, is as follows (in thousands):

6

VAXART, INC.

Notes to Unaudited Pro Forma Condensed Combined Financial Information

December 31, 2017

The application of the acquisition method of accounting is dependent upon certain valuations and other studies that are preliminary and have yet to be completed. The purchase price allocation will remain preliminary until the Combined Company’s management determines the fair values of assets acquired and liabilities assumed. The final determination of the purchase price allocation is anticipated to be completed as soon as practicable after completion of the transaction and will be based on the fair values of the assets acquired and liabilities assumed as of the transaction closing date. The final amounts allocated to assets acquired and liabilities assumed could differ significantly from the amounts presented in the unaudited pro forma condensed combined financial statements for the reasons described in Note 1.

(3)     Unaudited Pro Forma Adjustments

The unaudited pro forma condensed combined financial statements include pro forma adjustments to give effect to certain significant transactions of the Combined Company as a direct result of the merger, or for accounting purposes, the acquisition of Aviragen’s net assets by Private Vaxart. The pro forma adjustments reflecting the completion of the merger are based upon the conclusion that the merger should be accounted for as a business combination and upon the assumptions set forth below.

Adjustments included in the column under the heading “Pro Forma Adjustments” relate to the following:

7

VAXART, INC.

Notes to Unaudited Pro Forma Condensed Combined Financial Information

December 31, 2017

8