Oral Tablet H1 Influenza Vaccine vs Fluzone

Vaxart VXA-A1.1 Oral Flu Vaccine met Phase 2 clinical study end points
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The results of a phase 2 study indicate that an oral tablet for influenza vaccination, VXA-A1.1, can protect people against the flu virus just as well as Fluzone, which is a leading injectable quadrivalent influenza vaccine. 

“In all our studies to date, we have seen both systemic and mucosal immune responses, and this latest data provides solid evidence that our vaccines indeed protect through mucosal immunity, the first line of defense against mucosal infections,” said Wouter Latour, M.D., chief executive officer of Vaxart. 

This limited, Phase 2 randomized, placebo- and active-controlled, two-part study where healthy adults with low or undetectable pre-existing antibodies against A/California/7/2009(H1N1) pdm09-like virus, were challenged with an influenza A/H1N1 human strain.   

These study participants received approximately 90 days after vaccination a single dose of H1N1 HA Adenoviral-vector based seasonal influenza vaccine and dsRNA adjuvant (VXA-A1.1), an injectable QIV vaccine, and/or placebo. 

“These latest results show that our vaccine elicited a significant expansion of mucosal homing receptor α4β7+ (β7+) plasmablasts to approximately 60% of all activated B cells, while Fluzone only maintained baseline levels of 20%,” said Sean Tucker Ph.D., chief scientific officer of Vaxart, in a press release.   

“We believe these β7+ plasmablasts are a key indicator of a protective mucosal immune response and a unique feature of our oral recombinant vaccines.”

“Further analysis of the data also confirm that, while our vaccine also generated protective hemagglutinin inhibition (HAI) antibodies in serum like conventional injectable flu vaccines, it primarily protected through the mucosal mechanism, providing a robust 39% reduction in illness versus placebo overall.” 

“In contrast, Fluzone, the market-leading injectable quadrivalent influenza vaccine, only provided a 27% reduction in illness versus placebo, while protecting primarily through HAI antibodies,” said Dr. Tucker. 

Vaxart previously reported data from a phase 1 study where only 37% of study participants receiving the Vaxart vaccine developed influenza infection after challenge, compared to 44% of those receiving Fluzone and 71% of those receiving placebo.

The flu is a contagious respiratory illness caused by influenza viruses that infect the nose, throat and sometimes the lungs. It can cause mild to severe illness, and at times, can lead to death, says the Centers for Disease Control and Prevention (CDC). 

“We believe this clearly differentiates our oral vaccines from conventional injectable vaccines, and strongly suggests that vaccines based on Vaxart’s proprietary vector adjuvant system could be optimal to protect against mucosal pathogens, including some of the major public health threats such as flu, norovirus, RSV and many others,” said Dr. Latour. 

“Many patients are afraid to get traditional vaccines due to fear of injections or needles,” said  Lauren Ragan PharmD, Clinical Pharmacist, MTM and Immunization Specialist at Brookshire Grocery Company.

“This promising oral flu vaccine could help reach patients who normally wouldn’t get a flu shot and improve overall vaccination rates.”

The new Phase 2 data to be presented at IDWeek 2018.

The Phase 2 study was completed with support from Biomedical Advanced Research and Development Authority (BARDA). Vaxart received a $13.9 million contract from BARDA in September 2015 to support the advanced development of more effective influenza vaccines to ultimately improve seasonal and pandemic influenza preparedness. The contract was increased to $15.7 million in 2017. 

Various commercial relationships were disclosed by these researchers.

Vaxart is a clinical-stage biotechnology company focused on developing oral recombinant protein vaccines based on its proprietary oral vaccine platform.