A Booster Dose of Ad5-EBOV in Healthy Adults After Primary Immunization

Inclusion Criteria: * Participants who enrolled in the initial study, and completed the primary vaccination. * Able to understand the content of the additional informed consent and willing to sign the additional informed consent for the boosting study * Able and willing to complete a one-month follow-up. * HIV negative * Axillary temperature ≤37.0°C on the day of enrollment * General good health as established by medical history and physical examination. Exclusion Criteria: New occurrence of any of the following situation after the primary vaccination: * Subject that has a medical history of any of the following: allergic history of any vaccination or drugs, or allergic to any ingredient of the Ad5-EBOV vaccine, such as mannitol * Woman who become pregnant after the primary vaccination or is positive in β-HCG (human chorionic gonadotropin) pregnancy test (urine) on day of enrollment for the boosting study * Any acute fever disease or infections in last 7 days * Not well-controlled chronic illness, such as asthma, diabetes, or thyroid disease * Hereditary angioneurotic edema or acquired angioneurotic edema * Urticaria in last 6 months * Asplenia or functional asplenia * Platelet disorder or other bleeding disorder may cause injection contraindication * Faint at the sight of blood or needles. * Prior administration of immunodepressant or corticosteroids, antianaphylaxis treatment, cytotoxic treatment in last 6 months * Prior administration of blood products in last 4 months * Prior administration of other research medicines in last 1 month * Prior administration of attenuated vaccine in last 1 month * Prior administration of inactivated vaccine in last 14 days * Current anti-tuberculosis prophylaxis or therapy * Any condition that in the opinion of the investigators may interfere with the evaluation of study objectives