On Mar. 15, 2021, Altimmune announced additional preclinical data for its single dose intranasal COVID-19 vaccine candidate, AdCOVID. The preclinical studies were conducted at Altimmune’s collaborating institutions, the University of Alabama at Birmingham (UAB) and Saint Louis University. Based on data from Altimmune’s other intranasal platform vaccine candidates, AdCOVID was expected to have extended stability at room temperature that would allow for cold chain-free shipment of the vaccine.

The data, which were obtained in the K18-hACE2 transgenic mouse model, showed that a single intranasal dose of AdCOVID provided 100% protection against a lethal challenge from the SARS-CoV-2 virus. In these studies, which were performed in the laboratories of James Brien Ph.D., and Amelia Pinto Ph.D., within the Department of Molecular Microbiology & Immunology at SLU, all animals that received AdCOVID survived and had no observed weight loss.

Initial immunogenicity analysis showed mean antibody levels of about 1 mg/mL, suggesting that the serum IgG antibody response against the spike protein was robust, similar to what was reported in prior Company announcements. In a separate study at UAB in the laboratory of Dr. Frances Lund that was conducted in the same animal model, a single intranasal dose of AdCOVID resulted in a greater than 1000-fold reduction in replicating virus in the nasal cavity and respiratory tract following infection with SARS-CoV-2.