AdCOVID™

In February 2020, Altimmune deployed its platform technology to develop a single-dose intranasal vaccine for COVID-19 (AdCOVID). The company has recently announced compelling animal data on AdCOVID in collaboration with the University of Alabama at Birmingham (UAB) and plans to initiate a Phase 1 clinical trial of
AdCOVID in Q4 2020. Altimmune anticipates a data readout from this trial in Q1 2021 and the launch of an advanced development program soon thereafter.

The Only Intranasal COVID-19 Vaccine Candidate Poised to Enter Human Clinical Trials in 2020:

AdCOVID was designed to stimulate a broad immune response including both systemic immunity (neutralizing IgG) and local immunity (mucosal IgA, T cells) in the nasal cavity and respiratory tract. Local mucosal immunity is important to block SARS-CoV-2 viral replication in the nose – the point of disease initiation and spread. Recent studies have shown that in the absence of mucosal immunity, the nasal cavity may become a reservoir for the coronavirus, putting the patient at risk for reinfection or disease transmission to others. Importantly, nasal mucosal immunity can only be achieved by administering a vaccine intranasally, not intramuscularly.

Highly Potent Responses in a Relevant Animal Model:

Altimmune recently announced the results of highly successful animal studies that demonstrated strong activation of the three critical arms of the immune system following a single intranasal dose of AdCOVID—namely serum neutralizing activity, T cell immunity and mucosal immunity. AdCOVID is unique among the COVID-19 vaccines in development in demonstrating all of the following:

• Serum Neutralizing Activity: A serum neutralization titer of 1:580 by Day 28, several fold higher than the minimum titer recommended by the FDA – which is based upon measurements in convalescent plasma for experimental treatments of COVID-19.
• T cell Immunity: A potent stimulation of antigen specific CD8+ killer T cells in the lungs of mice as early as 10 days after vaccination.
• Mucosal Immunity: A 29-fold increase in mucosal IgA, well above the level associated with protection in clinical studies of other vaccines. Mucosal immunity can stop both infection and spread of the virus.]

Superior Product Stability:

The stability, or shelf-life, of a COVID-19 vaccine is also a critical consideration. Unlike other COVID-19 vaccine candidates that must be stored and shipped at ultra-low freezer temperatures
and have a shelf-life of only days in a refrigerator, our vaccines are stable for years when refrigerated and can withstand months at room temperature. The ability to distribute vaccine without cold-chain requirements will allow for more efficient distribution logistics. Dependable, on-site availability of vaccines will be a critical issue for community clinics and pharmacies, as ultra-low freezers are not available in most institutions.

Public Appeal of a Simple Nasal Spray:

AdCOVID is administered as a simple nasal spray and has the potential to bring a wide range of unique benefits to protect the public and address unmet needs:

• Less invasive than an injection
• Can be self-administered
• Packaged with self-contained nasal spray device for ease of deployment
• Can be shipped without refrigeration directly to the patient

Important Differentiations from Other COVID-19 Vaccine Candidates in Development:

As shown in the table below, Altimmune’s AdCOVID offers important differentiations from other vaccine candidates currently in clinical development for COVID-19.