Technology Renaissance Vaxart’s platform technology can produce against virtually any in the form of an oral pill rather than an injection. These orally delivered vaccines have the potential to revolutionize the vaccine marketplace. Vaxart filed an IND in March 2011 for its lead program, a vaccine for avian influenza H5N1. A variety of market-validated vaccine targets are in preclinical development. Commercial Opportunity

Vaccines are the most rapidly growing segment of the Pharma - ceutical market, and an active Vaxart Technology: Breakthrough Oral Vaccine Platform area of investment. The global market today is nearly $15 billion. US Advantage in Design Vaccine vector re-use, with Adenovirus or any other vector, has always been prevented by the annual flu alone has nearly $2.5 bil - Vaxart’s advantage flows from a complete re- patient’s immune response against the vector lion in sales. thinking of vaccine technology. Vaccines are itself. That immune response can come from composed of three basic elements: an antigen, Oral versions of current vaccines will previous exposure to the wild-type virus (Aden - the disease protein that is the target of the de - greatly expand many vaccine mar - ovirus causes common colds) or prior vaccina - sired immune response; an adjuvant, a kets. For instance, we expect an oral tion using the vector. annual flu vaccine to increase the "booster" molecule to stimulate the immune re - Vaxart has eliminated this problem with a two- projected market by at least $2 bil - sponse; and a delivery vehicle. fold approach: First, reduced immune surveil - lion by 2020. Vaxart's difference lies in its adjuvant and vector lance in the gut means the vaccine can work design – components with established safety, Regulatory advantages make avian despite previous exposure. Second, Vaxart’s ap - but used in a completely new way to form the flu a strategic first step: avian flu vac - proach does not generate a significant immune company’s breakthrough oral delivery platform. cines are a priority for regulatory response to any component of the vector back - agencies, and Phase III trials are not Powerful Adjuvant System bone, so that anti-vector immunity will not be - needed for commercial sales to stock - Vaxart uses an adjuvant that works through a come a problem. piles. Vaxart has filed an IND in toll-like receptor (TLR). TLRs have been widely 2011. Modular Vaccine Creation applied in vaccines and are well accepted as ef - By applying the same vector across its portfolio, The annual flu market, with a new fective immune stimulators. vaccine each year, plays directly to Vaxart can pursue a modular, standardized Vaxart’s approach differs in that it employs Vaxart’s advantages of rapid develop - approach to vaccine development. Vaxart does TLR3, the only TLR known to be fully active ment and efficient manufacturing. this by way of a common “skeleton” with the in the gastrointestinal tract. This means that Furthermore, safety data and manu - specific target antigen swapped in. This ap - Vaxart's vaccines can stimulate a strong, facturing experience with avian flu proach supports rapid and low cost develop - reliable immune response when administered will apply directly to an annual flu ment, but more importantly, reduces regulatory orally. In contrast, adjuvants used in most vac - product. Vaxart completed preclini - risk. Safety data from one vaccine will directly cines (marketed or in development) are inactive cal studies for avian influenza in support others created with the platform. In a or poorly active in the gut, requiring injection to 2010. case study with H1N1(2009), 100% protective ensure a protective immune response. vaccine was generated in 17 days. Intellectual Property Unique Reusable Vector Room Temperature Stability Vaxart has filed broadly and interna - A single effective oral vaccine is good. Even better The Vaxart oral dosage form is inherently ther - tionally on its proprietary technology. is the ability to create a whole series of oral vac - mostable. Vaxart has already shown a month Claims have issued in the US that cover cines using the same technology. of room temperature stability without signifi - the workable space for oral vaccination For its delivery vehicle, Vaxart uses a nonreplicat - cant loss of potency. It is expected that the final using TLR3 agonists and adenovirus, as ing adenovirus. Adenoviruses have been em - released product can be transported and dis - well as the use of the TLR3 agonist cre - ployed before; however, only Vaxart is able to use tributed without refrigeration, a substantial ated by Vaxart. All IP is owned by the same vector backbone for all of its vaccines. benefit for countries without a cold-chain. Vaxart without university or govern - ment encumbrances.

Safety: Abundant Precedent All components of the Vaxart vaccine have been tested in humans. Replicating adenoviruses were given orally to millions of military personnel in an FDA approved vaccine for 3 decades and had an outstanding safety record. Vaxart’s non-replicating vectors should have even fewer con - cerns. TLR3 agonists have been in several late stage clinical trials with much more aggressive quantities and administration frequencies than for Vaxart’s vaccine. Phase I safety and immunogenicity trials will begin in 2011 for Vaxart’s avian influenza vaccine. Vaxart Oral Delivery Approach Achieves Key Performance Goals Management Michael Finney, PhD G Chief Executive Officer G Produces a protective G Generates negligible Repeatedly produces a anti-vector significant immune response Dr. Finney has been involved with immune response using early stage manage - oral delivery immune response in a series of vaccines ment for over 20 years. 10 5 Sean Tucker, PhD Production Vaccine Target Percent Titer 4

r Sequence Antigen vs Naive Founder and Chief Scientific Officer 10 Against Against Antigen e Route t

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Dr. Tucker has more than 15 years A 100 2 Avian Flu ≥ 100% experience in pharmaceutical IM 20,000 10,000 2:1 3 Influenza ≥ 100% research and development. Before 10 founding Vaxart, he was a senior Vaxart Oral adeno IM scientist in vaccine delivery Oral w/out adju - adeno vant technology at Genteric. John Cornwell, MBA VP Business Development Protection Against Viral Challenge, Across Virus Strains Mr. Cornwell has over 20 years in Vaxart oral vaccine protected against avian flu in Challenge Results: product and business develop - both large- and small-animal efficacy studies. Vaxart ment experience at companies in - Protection against sickness and death cluding Genentech, Cell Genesys, has also shown that it can protect animals against Abgenix (Amgen). 100X the minimum lethal dose in a VEE aerosol chal - Challenge Protection Model David Madden, MBA lenge model as well as against 2009 H1N1 in a rapid Chief Financial Officer response vaccine test. In the H1N1 vaccine test, Avian Influezna Sickness and Death Ferret, Mouse VEE Death, 100X LD50 Mouse Mr. Madden has more than twenty 100% protective vaccine was generated in 17 days years experience in corporate fi - from receipt of the HA gene. H1N1(2009) Sickness and Death Mouse nance. Prior to Vaxart, he was CFO of Arriva Pharmaceuticals and held various finance positions while at Chiron. Vaxart’s oral vaccine (Vaxart Oral) has repeatedly Selective Response Against Influenza shown the ability to generate that pro - by Oral Board of Directors tect against more than just the single strain used Michael Finney, PhD to make the vaccine. While both muscle vaccina - ferret, HAI and anti-Ad Vector Life Science Angels tion (adeno IM) and Oral Vaxart induced neutral - neutralizing Titer izing antibody responses to strain matched Jan Leshley 1000 HAI A/Indo influenza (HAI A/Indo)*, ferrets receiving Vaxart’s Care Capital r HAI A/VN e

t anti-vector Dick Markham oral vaccine developed significant cross-clade i T

Care Capital neutralizing antibodies (HAI A/VN) and no anti- t u

e 100 vector responses whereas muscle vaccination (IM Sean Tucker, PhD N g

Vaxart, Inc. Adeno) induced no cross-clade response and a sig - v nificant anti-vector response. A Scientific Advisors 10 Harry Greenberg, MD, Stan - Vaxart adeno ford University *Hemagglutinin Inhibition titer (HAI) Oral I.M. Scott Weaver, PhD, University of Texas, MB Richard Whitley , MD University of Alabama at Breadth of Immunity - Better with Vaxart Oral Vector Birmingham Mucosal Immunity Induced T cell Immune Responses Better by Oral Delivery than Protein Vaccines

Injected vaccines induce poor mucosal im - Adenoviral vectors induce stronger T cell immune responses than corresponding pro - 20 California St, 7 th Floor mune responses, yet 90% of pathogens in - tein vaccines. Vaxart has demonstrated San Francisco, CA 94111 vade through a mucosal surface. Vaxart’s oral delivery induces immunity in the gas - CD8 T cell responses better than alum, Phone: +1.415.437.0132 trointestinal track, the lungs, and vagina AS04, and adjuvants with protein vaccines. Fax: +1.415.863.1274 www.vaxart.com

Contact: bd @vaxart.com