It's also unlikely to be very effective due to it using the adenovirus Ad5 as a vector, which is a human adenovirus that many people have antibodies against. This means a marked loss of efficacy if you have them.
If you read the study, it states that even in recipients with high Ad5 immunity, as long as the dose is sufficient (high-dose or medium dose) long-term seroconversion is high - 84% to 100% in medium or high dose after 28 days for recipients with strong antibodies against Ad5, and for high-dose seroconversion and interferon gamma response was indistinguishable from those without strong Ad5 immunity. [0, fig 1 - Specific T-cell response measured by ELISpot].
So I don't really think it will be an issue. You just need the proper dose. : https://www.thelancet.com/journals/lancet/article/PIIS0140-6...