- Very immunogenic: strong T-cell responses (especially CD8+) due to intracellular antigen expression and potent innate sensing of the vector. Often effective with a single dose (e.g. J&J’s Ad26 COVID vaccine), which is useful in outbreak control. Can target mucosal immunity by using vectors that infect via mucosal routes (e.g. intranasal adenovirus for respiratory pathogens). Track record of licensed products (Ebola, COVID vectors) gives regulatory and manufacturing know-how. Here, CD8A is linked to Ebola hemorrhagic fever.