Read the latest professional publications with preliminary findings and reviews of Vaxart’s approach to vaccine pill delivery to address areas of unmet need.
An adjuvanted adenovirus 5-based vaccine elicits neutralizing antibodies and protects mice against chikungunya virus-induced footpad swelling
Source: Dora EG, Rossi SL, Weaver SC, Tucker SN, Mateo R. Vaccine. 2019 May 27;37(24):3146-3150. doi: 10.1016/j.vaccine.2019.04.069. Epub 2019 Apr 29.
Safety and immunogenicity of an oral tablet norovirus vaccine, a phase I randomized, placebo-controlled trial
Source: Kim L, Liebowitz D, Lin K, Kasparek K, Pasetti MF, Garg SJ, Gottlieb K, Trager G, Tucker SN. JCI Insight. 2018 Jul 12;3(13). pii: 121077. doi: 10.1172/jci.insight.121077. [Epub ahead of print]
Systemic and mucosal immune responses following oral adenoviral delivery of influenza vaccine to the human intestine by radio controlled capsule
Source: Kim L, Martinez CJ, Hodgson KA, Trager GR, Brandl JR, Sandefer EP, Doll WJ, Liebowitz D, Tucker SN. Sci Rep. 2016 Nov 24;6:37295. doi: 10.1038/srep37295
Oral Modeling of an Adenovirus-Based Quadrivalent Influenza Vaccine in Ferrets and Mice
Source: Scallan CD, Lindbloom JD, Tucker SN. Infectious Diseases and Therapy. 2016;Apr 12. [Epub ahead of print] doi: 10.1007/s40121-016-0108-z.
Introduction: Oral vaccines delivered as tablets offer a number of advantages over traditional parenteral-based vaccines including the ease of delivery, lack of needles, no need for trained medical personnel, and the ability to formulate into temperature-stable tablets. We have been evaluating an oral vaccine platform based on recombinant adenoviral vectors for the purpose of creating a prophylactic vaccine to prevent influenza, and have demonstrated vaccine efficacy in animal models and substantial immunogenicity in humans. These studies have evaluated monovalent vaccines to date. To protect against the major circulating A and B influenza strains, a multivalent influenza vaccine will be required.
Methods: In this study, the immunogenicity of orally delivered monovalent, bivalent, trivalent, and quadrivalent vaccines was tested in ferrets and mice. The various vaccine combinations were tested by blending monovalent recombinant adenovirus vaccines, each expressing hemagglutinin from a single strain. Human tablet delivery was modeled in animals by oral gavage in mice and by endoscopic delivery in ferrets.
Results: We demonstrated minimal interference between the various vaccine vectors when used in combination and that the oral quadrivalent vaccine compared favorably to an approved trivalent inactivated vaccine.
Conclusion: The quadrivalent vaccine presented here produced immune responses that we predict should be capable of providing protection against multiple influenza strains, and the platform should have applications to other multivalent vaccines.
High Titre Neutralising Antibodies to Influenza after Oral Tablet Immunisation: A Phase 1, Randomised, Placebo-Controlled Trial
Source: Liebowitz D, Lindbloom JD, Brandl JR, Garg SJ, Tucker SN. Lancet Infectious Diseases. 2015 Sep;15(9):1041-8. doi: 10.1016/S1473-3099(15)00266-2.
Oral Administration of an Adenovirus Vector Encoding Both an Avian Influenza A Hemagglutinin and a TLR3 Ligand Induces Antigen Specific Granzyme B and IFN-Γ T Cell Responses in Humans
Source: Peters W, Brandl JR, Lindbloom JD, Martinez CJ, Scallan CD, Trager GR, Tingley DW, Kabongo ML, Tucker SN. Vaccine. 2013;Mar 25;31(13):1752-8. doi: 10.1016/j.vaccine.2013.01.023. Epub 2013 Jan 25.
An Adenovirus-Based Vaccine with a Double-Stranded RNA Adjuvant Protects Mice and Ferrets against H5N1 Avian Influenza in Oral Delivery Models
Source: Scallan CD, Tingley DW, Lindbloom JD, Toomey JS, Tucker SN. Clin Vaccine Immunol. Published ahead of print 14 November 2012, doi:10.1128/CVI.00552-12.
An oral gene-based avian influenza vaccine would allow rapid development and simplified distribution, but efficacy has previously been difficult to achieve by the oral route. This study assessed protection against avian influenza virus challenge using a chimeric adenovirus vector expressing hemagglutinin and a double-stranded RNA adjuvant. Immunized ferrets and mice were protected upon lethal challenge. Further, ferrets immunized by the peroral route induced cross-clade neutralizing antibodies, and the antibodies were selective against hemagglutinin, not the vector. Similarly, experiments in mice demonstrated selective immune responses against HA with peroral delivery and the ability to circumvent preexisting vector immunity.
Oral Adenoviral-Based Vaccines: Historical Perspective and Future Opportunity
Source: Tucker SN, Tingley DW, Scallan CD. Expert Review of Vaccines. 2008;7(1),25–31.
Adenoviral vaccines delivered orally have been used for decades to prevent respiratory illness, but are now being seriously explored again as a platform technology to make vaccines against a variety of pathogens. Years of use in military populations as a preventative measure for adenoviral infection have demonstrated the safety of oral administration of adenovirus. The advantages of using this approach as a platform technology for vaccines include rapid development and distribution, as well as ease of administration. Recent discoveries may allow this platform approach to reach the clinic within a few years.