In a new study, researchers found positive results that distinguish a new COVID-19 vaccine candidate from other vaccine candidates that are currently in advanced stages of clinical development.
Unlike the other candidates that are administered by an intramuscular shot, the Altimmune candidate, AdCOVID, is administered by a single intranasal spray.
In animal models at UAB, that single dose 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 research was conducted by a team at the University of Alabama at Birmingham.
This news follows the July announcement by Altimmune that the vaccine candidate—tested as an intranasal spray in mice by UAB researchers—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 an 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.
This local mucosal immune response is an important addition to the systemic immune response and has the potential to block infection and prevent transmission.
In addition to potent immunogenicity after a single dose administration, AdCOVID is expected to show further benefits in terms of vaccine distribution and administration.
Intranasal dosing provides AdCOVID with the potential to be administered rapidly and without the need for needles, syringes or trained health care personnel.
Also, the expected room temperature stability of AdCOVID may allow the broad distribution of the vaccine without the need for expensive cold-chain logistics, such as refrigeration or freezing.
Altimmune is currently manufacturing AdCOVID for a human Phase 1 safety and immunogenicity study, expected to begin in the fourth quarter of 2020.
One researcher of the study is Frances Lund, Ph.D., the Charles H. McCauley Professor.
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