Scot Roberts
Analyst · Piper Sandler. Please proceed with your question
Thank you, Vipin, and good morning. We have made excellent progress, toward our Phase I clinical trial of AdCOVID, a single-dose intranasal vaccine candidate for COVID-19. Earlier this year, we created different vaccine candidates based on our respira-vac replication-deficient adenovirus vaccine platform. Candidates, expressing different portions of the viral spike protein, were evaluated in a series of preclinical studies performed by our collaborators at the University of Alabama, at Birmingham. Based on those results, we selected the candidate that expressed the receptor-binding domain or RBD of this viral spike protein for clinical development. The RBD is essential for viral infection. And the great majority of neutralizing antibodies in convalescent [serum] [ph] are directed against the RBD. So it's clearly an important target for the immune system. In our preclinical mouse studies a single intranasal dose of AdCOVID, stimulated strong serum antibody responses, and [high] [ph] virus neutralizing titers. Importantly, AdCOVID also induced a very robust mucosal IgA antibody response, in the respiratory tract. Mucosal IgA is a special type of immunity that is produced locally to provide local protection, from infection. When stimulated in the respiratory tract, mucosal immunity offers a potential to not only block infection, but also block transmission of the virus to others. By far, the most important way to induce a nasal IgA response is to administer the vaccine intranasally. Bear in mind, that all of the vaccine candidates, in advanced clinical testing are delivered by intramuscular injection. Not only is that method of dosing more complicated than intranasal dosing, it's also unlikely to elicit mucosal IgA immunity, in the respiratory tract. The presence of nasal IgA maybe especially important for protection from COVID-19 because of two important considerations. One, the SARS-CoV-2 virus replicates well in the nasal cavity. And two, antibodies against the virus that are in your blood, can't get into the nasal cavity very well. So in the absence, of local mucosal IgA immunity, the nasal cavity may become a safe haven for the virus. Over the next few weeks, we'll be reporting on the ability of AdCOVID, to stimulate T-cell immunity, a third type of immunity we expect to stimulate, in addition to the neutralizing antibody and mucosal IgA responses. Once we have the T-cell data in hand, we plan to quickly publish the preclinical data, so we can share it with the scientific community. Now, having identified the vaccine candidate we are taking forward, we initiated a dual-track approach, towards the manufacturing of AdCOVID. While moving quickly to provide clinical trial material to conduct our Phase I trial later this year, we will begin scaling the manufacturing process in parallel, to meet the requirements of Phase III testing and commercial launch of AdCOVID. To accomplish these aggressive goals, we have established multiple alliances, with key manufacturing partners that have deep experience, in the manufacturing of viral vectors. Notably, we are using the same manufacturing process for AdCOVID as for our other vaccine candidates, including our NasoShield intranasal anthrax vaccine that we are developing with BARDA; and NasoVAX our intranasal influenza vaccine. Using the same manufacturing process allows us to manufacture quickly and with confidence. Additionally, vaccine candidates based on our respira-vac platform have shown excellent stability at room temperature potentially allowing for the distribution of AdCOVID without the refrigeration or freezing that is normally required for other vaccines greatly simplifying getting the vaccine to those who need it. With that, I will turn the call over to Scott Harris, who will provide a clinical update on our programs. Scott?