This is a single center, open, dose-escalation clinical trial. According to the Chinese guidelines for vaccine clinical trial, the sample size of a phase 1 clinical trial should be at least 20. In this study, a total of 60 participants will be included.30 participants will be firstly recruited and assigned to receive the low dose Ad5-EBOV. After the safety of the low dose vaccination is confirmed, another 30 participants will be recruited and assigned to receive the high dose Ad5-EBOV.