Preclinical studies of a COVID-19 vaccine candidate at UAB show results that distinguish it from other vaccine candidates that also are in the advanced stages of clinical development, Maryland-based Altimmune announced Tuesday.

AdCOVID is a single dose, intranasal spray. In animal models at UAB, it’s use resulted in a potent T-cell response at the mucus layer of the lungs, including killer CD8+ T-cells, which can recognize and kill virally infected cells.

Recent reports have suggested the importance of T-cell responses for long-term protection from COVID-19.

“The mucosal T-cell response in the respiratory tract is believed to be dependent on the intranasal route of administration, and we believe it has the potential to provide additional protection against COVID-19,” Altimmune stated. “The induction of a mucosal T-cell response in the lungs has not been shown, to date, with the intramuscularly administered COVID-19 vaccine candidates that are currently in the advanced stages of clinical development.”

UAB researchers announced in July that tests of the spray in mice prompted a mouse immune response in the blood that was strong enough to neutralize the COVID-19 virus, as well as a potent immune response in the respiratory tract — the site where the COVID-19 virus first infects.

The vaccine candidate creates an immune response against the COVID-19 virus spike protein that helps the virus bind to a human cell to start infection.

“The property that sets AdCOVID apart is that it has been shown preclinically to induce a potent T-cell and IgA antibody response in the lungs, in addition to the systemic neutralizing antibody response induced by intramuscular vaccine candidates,” Dr. Frances Lund, the Charles H. McCauley Professor and chair of the UAB Department of Microbiology and lead investigator for preclinical testing of the AdCOVID vaccine candidates, said in a statement. “This local mucosal immune response is an important addition to the systemic immune response and has the potential to block infection and prevent transmission.”

Altimmune is currently manufacturing AdCOVID for a human Phase 1 safety and immunogenicity study, expected to begin in the fourth quarter of 2020.