Drop the Needle; A Temperature Stable Oral Tablet Vaccine Is Protective against Respiratory Viral Pathogens.

To effectively combat emerging infections and prevent future pandemics, next generation vaccines must be developed quickly, manufactured rapidly, and most critically, administered easily. Next generation vaccines need innovative approaches that prevent infection, severe disease, and reduce community transmission of respiratory pathogens such as influenza and SARS-CoV-2. Here we review an oral vaccine tablet that can be manufactured and released in less than 16 weeks of antigen design and deployed without the need for cold chain. The oral Ad5 modular vaccine platform utilizes a non-replicating adenoviral vector (rAd5) containing a novel molecular TLR3 adjuvant that is delivered by tablet, not by needle. This enterically coated, room temperature-stable vaccine tablet elicits robust antigen-specific IgA in the gastrointestinal and respiratory tracts and upregulates mucosal homing adhesion molecules on circulating B and T cells. Several influenza antigens have been tested using this novel vaccine approach and demonstrated efficacy in both preclinical animal models and in phase I/II clinical trials, including in a human challenge study. This oral rAd5 vaccine platform technology offers a promising new avenue for aiding in rapid pandemic preparedness and equitable worldwide vaccine distribution.

Development and pre-clinical evaluation in the swine model of a mucosal vaccine tablet for human influenza viruses: A proof-of-concept study.

Liquid vaccine formulations present some disadvantages such as stability problems, cold chain requirement or administration by trained personnel. Vaccine formulated as tablets would present a wide range of progress such as an increase stability that would facilitate the administration, the distribution and the storage of vaccine formulations. This work investigates the possibility to develop a mucosal tablet vaccine for human influenza viruses. The tablets were tested in vitro for biological efficacy and stability and in vivo in swine as a model for influenza A virus immunity. First, the ability to produce by compaction a stable vaccine with a preserved antigen was demonstrated. In a second part, vaccine tablets were used to immunize pigs. After positioning the tablets on the buccal mucosa, the animals were challenged by inoculation of the A/H1N1 pandemic virus. The responses were compared to those observed in animals vaccinated intramuscularly with the commercial liquid vaccine. It was observed signs of priming of the pig's immune system with vaccine tablets, even if the immune response stayed lower than vaccination by intramuscular route. Thus, we present attractive results that indicate a promising potential for mucosal vaccine tablets.