A booster vaccination of replication defective MVA-BN-Filo administered by an IM injection into the deltoid as a single dose of 1 x 10^8 Infectious Units (IU).

0.5 mL normal saline administered via IM injection into the deltoid.

Local reactogenicity solicited on a memory aid provided to participants included pain, tenderness, erythema (redness) (functional grade based on interference with daily activities), induration (hardness/swelling) (functional grade), ecchymosis (bruising) (functional grade), pruritus (itching), erythema (redness) (any measured value), induration (hardness/swelling) (any measured value), ecchymosis (bruising) (any measured value). Subjects are considered reporting the local reactogenicity if they reported mild or greater severity at any time during the 7 days post-vaccination.

Systemic reactogenicity solicited on a memory aid provided to participants included feverishness (chills/shivering/sweating), malaise (general unwell feeling), fatigue (tiredness), myalgia (body aches/muscular pain not at injection site), headache, nausea, loss of appetite, and elevated oral temperature. Participants are considered reporting the systemic reactogenicity if they reported mild or greater severity at any time during the 7 days post-vaccination.

Systemic reactogenicity solicited on a memory aid provided to participants included feverishness (chills/shivering/sweating), malaise (general unwell feeling), fatigue (tiredness), myalgia (body aches/muscular pain not at injection site), headache, nausea, loss of appetite, and elevated oral temperature. Participants are considered reporting the systemic reactogenicity if they reported mild or greater severity at any time during the 7 days post-vaccination.

Systemic reactogenicity solicited on a memory aid provided to participants included feverishness (chills/shivering/sweating), malaise (general unwell feeling), fatigue (tiredness), myalgia (body aches/muscular pain not at injection site), headache, nausea, loss of appetite, and elevated oral temperature. Participants are considered reporting the systemic reactogenicity if they reported mild or greater severity at any time during the 7 days post-vaccination.

Vaccine-related MAAEs include any AEs for which the participant received medical attention, defined as hospitalization, an emergency room visit, or an otherwise unscheduled visit to or from medical personnel for any reason for which there is evidence to suggest a causal relationship between the study product and the adverse event.

Vaccine-related unsolicited AEs include any untoward medical occurrence in a participant for which there is evidence to suggest a causal relationship between the study product and the adverse event.

Thresholds for adverse events were considered as WBC 2.5 - 4.4 K/mcL or 13.1 - 15.0 K/mcL (18 to <21 years) or 2.5 - 4.4 K/mcL or 11.1 - 15.0 (>=21 years) (mild), 1.5 - 2.4 K/mcL or 15.1 - 20.0 K/mcL (moderate), <1.5 K/mcL or >20.0 K/mcL (severe). If baseline clinical labs fell within mild range, then a laboratory AE was reported only if the value changed such that it fell into moderate range or higher when subsequent safety laboratory testing was done.

Thresholds for adverse events were considered as hemoglobin 10.1 - 11.6 g/dL (female) or 11.0 - 13.2 (male) (mild), 8.5 - 10 g/dL (female) or 9.5 - 10.9 g/dL (male) (moderate), <8.5 g/dL (female) or <9.5 g/dL (male) (severe). If baseline clinical labs fell within mild range, then a laboratory AE was reported only if the value changed such that it fell into moderate range or higher when subsequent safety laboratory testing was done.

Thresholds for adverse events were considered as platelet count 125 - 134 K/mcL or 467 - 517 K/mcL (mild), 100 - 124 K/mcL or 518 - 750 K/mcL (moderate), <100 K/mcL or >750 K/mcL (severe). If baseline clinical labs fell within mild range, then a laboratory AE was reported only if the value changed such that it fell into moderate range or higher when subsequent safety laboratory testing was done.

Thresholds for adverse events were considered as absolute neutrophil count 1.5 - <1.8 K/mcL or 0.6 - 0.7 K/mcL (benign ethnic neutropenia) (mild), 1.0 - <1.5 K/mcL or 0.4 - 0.5 K/mcL (benign ethnic neutropenia) (moderate), <1.0 K/mcL or <0.4 K/mcL (benign ethnic neutropenia) (severe). If baseline clinical labs fell within mild range, then a laboratory AE was reported only if the value changed such that it fell into moderate range or higher when subsequent safety laboratory testing was done.

Thresholds for adverse events were considered as 50 - 123 unit/L (mild), 124 - 245 unit/L (moderate), >245 unit/L (severe). If baseline clinical labs fell within mild range, then a laboratory AE was reported only if the value changed such that it fell into moderate range or higher when subsequent safety laboratory testing was done.

Thresholds for adverse events were considered as creatinine 0.81 - 1.70 mg/dL (female) or 1.11 - 1.70 mg/dL (male) (mild), 1.71 - 2.00 mg/dL (moderate), >2.00 mg/dL (severe). If baseline clinical labs fell within mild range, then a laboratory AE was reported only if the value changed such that it fell into moderate range or higher when subsequent safety laboratory testing was done.

Thresholds for adverse events were considered as sodium 130 - 135 mmol/L or 146 - 150 mmol/L (mild), 123 - 129 mmol/L or 151 - 157 mmol/L (moderate), <123 mmol/L or >157 mmol/L (severe). If baseline clinical labs fell within mild range, then a laboratory AE was reported only if the value changed such that it fell into moderate range or higher when subsequent safety laboratory testing was done.

Thresholds for adverse events were considered as potassium 3.0 - 3.4 mmol/L or 5.2 - 6.0 mmol/L (mild), 2.5 - 2.9 mmol/L or 6.1 - 6.5 mmol/L (moderate), <2.5 mmol/L or >6.5 mmol/L (severe). If baseline clinical labs fell within mild range, then a laboratory AE was reported only if the value changed such that it fell into moderate range or higher when subsequent safety laboratory testing was done.

Thresholds for adverse events were considered as BUN 24 - 26 mg/dL (mild), 27 - 31 mg/dL (moderate), >31 mg/dL (severe). If baseline clinical labs fell within mild range, then a laboratory AE was reported only if the value changed such that it fell into moderate range or higher when subsequent safety laboratory testing was done.

Local reactogenicity solicited on memory aid include pain; tenderness; pruritus (itch); erythema (redness), induration (hardness/swelling), and ecchymosis (bruising) (functional and measurement). Thresholds for severity were pain: aware, no interference with activity, no pain med (mild), aware, interferes with activity or requires repeated use of a non-narcotic pain reliever for >24 hr (moderate), aware, prevents activity or requires prescription med use (severe); tenderness: area surrounding injection hurts when touched or with arm motion, no interference with daily activity (mild), hurts when touched or with arm motion, interferes with activity (moderate), hurts when touched or with arm motion and prevents activity (severe); functional erythema, induration, ecchymosis, and pruritus: no activity interference (mild), interferes with activity (moderate), prevents activity (severe); erythema, induration, and ecchymosis (measurement): <20mm (mild), 20 - 50mm (moderate), >50mm (severe).

Local reactogenicity solicited on memory aid include pain; tenderness; pruritus (itch); erythema (redness), induration (hardness/swelling), and ecchymosis (bruising) (functional and measurement). Thresholds for severity grading were pain: aware, no interference with activity, no pain med (mild), aware, interferes with activity or requires repeated use of a non-narcotic pain reliever for >24hr (moderate), aware, prevents activity or requires prescription med use (severe); tenderness: area surrounding injection hurts when touched or with arm motion, no interference with daily activity (mild), hurts when touched or with arm motion, interferes with activity (moderate), hurts when touched or with arm motion, prevents activity (severe); functional erythema, induration, ecchymosis, and pruritus: no activity interference (mild), interferes with activity (moderate), prevents activity (severe); erythema, induration, and ecchymosis (measurement): <20mm (mild), 20-50mm (moderate), >50mm (severe).

Local reactogenicity solicited on memory aid include pain; tenderness; pruritus (itch); erythema (redness), induration (hardness/swelling), and ecchymosis (bruising) (functional and measurement). Thresholds for severity grading were pain: aware, no interference with activity, no pain med (mild), aware, interferes with activity or requires repeated use of a non-narcotic pain reliever for >24hr (moderate), aware, prevents activity or requires prescription med use (severe); tenderness: area surrounding injection hurts when touched or with arm motion, no interference with daily activity (mild), hurts when touched or with arm motion, interferes with activity (moderate), hurts when touched or with arm motion, prevents activity (severe); functional erythema, induration, ecchymosis, and pruritus: no activity interference (mild), interferes with activity (moderate), prevents activity (severe); erythema, induration, and ecchymosis (measurement): <20mm (mild), 20-50mm (moderate), >50mm (severe).

Systemic reactogenicity solicited on memory aid included feverishness (chills/shivering/sweating), malaise (general unwell feeling), fatigue (tiredness), myalgia (body aches/muscular pain not at injection site), headache, nausea, loss of appetite, and elevated oral temperature. Thresholds for severity include feverishness, malaise, fatigue, myalgia, nausea, and loss of appetite: Noticeable but does not interfere with daily activity (Mild), Interferes with daily activity (Moderate), Significant interference, prevents daily activity (Severe); headache: Noticeable but does not interfere with daily activity (Mild), Any use of pain reliever or interferes with daily activity (Moderate), Significant interference, prevents daily activity, or requires any use of a prescription medication (Severe); elevated oral temperature: 37.8°C - 38.4°C or 100.00°F - 101.1°F (Mild), 38.5°C - 38.9°C or 101.2°F - 102.0°F (Moderate), >38.9°C or >102.0°F (Severe).

Systemic reactogenicity solicited on memory aid included feverishness (chills/shivering/sweating), malaise (general unwell feeling), fatigue (tiredness), myalgia (body aches/muscular pain not at injection site), headache, nausea, loss of appetite, and elevated oral temperature. Thresholds for severity include feverishness, malaise, fatigue, myalgia, nausea, and loss of appetite: Noticeable but does not interfere with daily activity (Mild), Interferes with daily activity (Moderate), Significant interference, prevents daily activity (Severe); headache: Noticeable but does not interfere with daily activity (Mild), Any use of pain reliever or interferes with daily activity (Moderate), Significant interference, prevents daily activity, or requires any use of a prescription medication (Severe); elevated oral temperature: 37.8°C - 38.4°C or 100.00°F - 101.1°F (Mild), 38.5°C - 38.9°C or 101.2°F - 102.0°F (Moderate), >38.9°C or >102.0°F (Severe).

Systemic reactogenicity solicited on memory aid included feverishness (chills/shivering/sweating), malaise (general unwell feeling), fatigue (tiredness), myalgia (body aches/muscular pain not at injection site), headache, nausea, loss of appetite, and elevated oral temperature. Thresholds for severity include feverishness, malaise, fatigue, myalgia, nausea, and loss of appetite: Noticeable but does not interfere with daily activity (Mild), Interferes with daily activity (Moderate), Significant interference, prevents daily activity (Severe); headache: Noticeable but does not interfere with daily activity (Mild), Any use of pain reliever or interferes with daily activity (Moderate), Significant interference, prevents daily activity, or requires any use of a prescription medication (Severe); elevated oral temperature: 37.8°C - 38.4°C or 100.00°F - 101.1°F (Mild), 38.5°C - 38.9°C or 101.2°F - 102.0°F (Moderate), >38.9°C or >102.0°F (Severe).

Vaccine-related unsolicited AEs include any untoward medical occurrence in a participant for which there is evidence to suggest a causal relationship between the study product and the adverse event. Thresholds for severity include events require minimal or no treatment and do not interfere with the subject's daily activities (mild), events result in a low level of inconvenience or concern with therapeutic measures and may cause some interference with functioning and daily activities (moderate), and events interrupt the subject's daily activities and may require systemic drug therapy or other treatment and are usually incapacitating (severe). Participants are counted once per preferred term and are summarized according to their highest severity. No severe events were reported.

The endpoint assessed antibodies against Ebola virus (EBOV) glycoproteins (GP) using an enzyme-linked immunosorbent assay (anti-EBOV GP ELISA). Venous blood samples for serum were used for this assay. Geometric mean fold rise (GMFR) compared to baseline (Day 1) was calculated for each study arm.

The endpoint assessed antibodies against Ebola virus (EBOV) glycoproteins (GP) using an enzyme-linked immunosorbent assay (anti-EBOV GP ELISA). Venous blood samples for serum were used for this assay. Geometric Mean Titer (GMT) was calculated for each study arm.

The endpoint assessed antibodies against Ebola virus (EBOV) glycoproteins (GP) using an enzyme-linked immunosorbent assay (anti-EBOV GP ELISA). Venous blood samples for serum were used for this assay. Geometric Mean Titer (GMT) was calculated for each study arm.

The endpoint assessed antibodies against Ebola virus (EBOV) glycoproteins (GP) using an enzyme-linked immunosorbent assay (anti-EBOV GP ELISA). Venous blood samples for serum were used for this assay. Seroconversion was calculated for each study arm and was defined as anti-EBOV GP ELISA titer > 50 if baseline (Day 1) titer = 50 or fold rise > 4 as compared to baseline if baseline titer > 50.

The endpoint assessed antibodies against Ebola virus (EBOV) glycoproteins (GP) using an enzyme-linked immunosorbent assay (anti-EBOV GP ELISA). Venous blood samples for serum were used for this assay. Seroconversion was calculated for each study arm and was defined as anti-EBOV GP ELISA titer > 50 if baseline (Day 1) titer = 50 or fold rise > 4 as compared to baseline if baseline titer > 50.

ChAd3-EBO-Z (2 x 10^11 virus particles (vp)) intramuscularly into the deltoid on Day 1 and ChAd3-EBO-Z (2 x 10^11 vp) intramuscularly into the opposite arm on Day 8.

ChAd3-EBO-Z: Zaire ebolavirus vaccine administered by an IM injection into the deltoid as a single dose of 2 x 10^11 virus particles (vp)).

ChAd3-EBO-Z (2 x 10^11 virus particles (vp)) intramuscularly into the deltoid on Day 1 and MVA-BN-Filo (1 x 10^8 Infectious Units (IU)) intramuscularly into the opposite arm on Day 8.

ChAd3-EBO-Z: Zaire ebolavirus vaccine administered by an IM injection into the deltoid as a single dose of 2 x 10^11 virus particles (vp)).

MVA Multi-Filo Ebola Vaccine: A booster vaccination of replication defective MVA-BN-Filo administered by an IM injection into the deltoid as a single dose of 1 x 10^8 Infectious Units (IU).

Total of all reporting groups

SAEs included any AE that resulted in death, a life-threatening event, an inpatient hospitalization or prolongation of existing hospitalization, a persistent/significant disability/incapacity, or a congenital anomaly/birth defect.

Safety Population: includes all participants who received at least one study vaccination

Local reactogenicity solicited on a memory aid provided to participants included pain, tenderness, erythema (redness) (functional grade based on interference with daily activities), induration (hardness/swelling) (functional grade), ecchymosis (bruising) (functional grade), pruritus (itching), erythema (redness) (any measured value), induration (hardness/swelling) (any measured value), ecchymosis (bruising) (any measured value). Participants are considered reporting the local reactogenicity if they reported mild or greater severity at any time during the 7 days post-vaccination.

Safety Population: includes all participants who received at least one study vaccination. All participants in all Study Arms received the same product (ChAd3-EBO-Z) at Day 1.

Local reactogenicity solicited on a memory aid provided to participants included pain, tenderness, erythema (redness) (functional grade based on interference with daily activities), induration (hardness/swelling) (functional grade), ecchymosis (bruising) (functional grade), pruritus (itching), erythema (redness) (any measured value), induration (hardness/swelling) (any measured value), ecchymosis (bruising) (any measured value). Participants are considered reporting the local reactogenicity if they reported mild or greater severity at any time during the 7 days post-vaccination.

Safety Population Subset: includes all participants who received the first and second study vaccination

Local reactogenicity solicited on a memory aid provided to participants included pain, tenderness, erythema (redness) (functional grade based on interference with daily activities), induration (hardness/swelling) (functional grade), ecchymosis (bruising) (functional grade), pruritus (itching), erythema (redness) (any measured value), induration (hardness/swelling) (any measured value), ecchymosis (bruising) (any measured value). Subjects are considered reporting the local reactogenicity if they reported mild or greater severity at any time during the 7 days post-vaccination.

Safety Population: includes all participants who received at least one study vaccination.

Systemic reactogenicity solicited on a memory aid provided to participants included feverishness (chills/shivering/sweating), malaise (general unwell feeling), fatigue (tiredness), myalgia (body aches/muscular pain not at injection site), headache, nausea, loss of appetite, and elevated oral temperature. Participants are considered reporting the systemic reactogenicity if they reported mild or greater severity at any time during the 7 days post-vaccination.

Safety Population: includes all participants who received at least one study vaccination. All participants in all Study Arms received the same product (ChAd3-EBO-Z) at Day 1.

Systemic reactogenicity solicited on a memory aid provided to participants included feverishness (chills/shivering/sweating), malaise (general unwell feeling), fatigue (tiredness), myalgia (body aches/muscular pain not at injection site), headache, nausea, loss of appetite, and elevated oral temperature. Participants are considered reporting the systemic reactogenicity if they reported mild or greater severity at any time during the 7 days post-vaccination.

Safety Population Subset: includes all participants who received the first and second study vaccination

Systemic reactogenicity solicited on a memory aid provided to participants included feverishness (chills/shivering/sweating), malaise (general unwell feeling), fatigue (tiredness), myalgia (body aches/muscular pain not at injection site), headache, nausea, loss of appetite, and elevated oral temperature. Participants are considered reporting the systemic reactogenicity if they reported mild or greater severity at any time during the 7 days post-vaccination.

Safety Population: includes all participants who received at least one study vaccination.

Vaccine-related MAAEs include any AEs for which the participant received medical attention, defined as hospitalization, an emergency room visit, or an otherwise unscheduled visit to or from medical personnel for any reason for which there is evidence to suggest a causal relationship between the study product and the adverse event.

Safety Population: includes all participants who received at least one study vaccination.

Vaccine-related unsolicited AEs include any untoward medical occurrence in a participant for which there is evidence to suggest a causal relationship between the study product and the adverse event.

Safety Population: includes all participants who received at least one study vaccination

Thresholds for adverse events were considered as WBC 2.5 - 4.4 K/mcL or 13.1 - 15.0 K/mcL (18 to <21 years) or 2.5 - 4.4 K/mcL or 11.1 - 15.0 (>=21 years) (mild), 1.5 - 2.4 K/mcL or 15.1 - 20.0 K/mcL (moderate), <1.5 K/mcL or >20.0 K/mcL (severe). If baseline clinical labs fell within mild range, then a laboratory AE was reported only if the value changed such that it fell into moderate range or higher when subsequent safety laboratory testing was done.

Safety Population: includes all Participants who received at least one study vaccination

Thresholds for adverse events were considered as hemoglobin 10.1 - 11.6 g/dL (female) or 11.0 - 13.2 (male) (mild), 8.5 - 10 g/dL (female) or 9.5 - 10.9 g/dL (male) (moderate), <8.5 g/dL (female) or <9.5 g/dL (male) (severe). If baseline clinical labs fell within mild range, then a laboratory AE was reported only if the value changed such that it fell into moderate range or higher when subsequent safety laboratory testing was done.

Safety Population: includes all participants who received at least one study vaccination

Thresholds for adverse events were considered as platelet count 125 - 134 K/mcL or 467 - 517 K/mcL (mild), 100 - 124 K/mcL or 518 - 750 K/mcL (moderate), <100 K/mcL or >750 K/mcL (severe). If baseline clinical labs fell within mild range, then a laboratory AE was reported only if the value changed such that it fell into moderate range or higher when subsequent safety laboratory testing was done.

Safety Population: includes all participants who received at least one study vaccination

Thresholds for adverse events were considered as absolute neutrophil count 1.5 - <1.8 K/mcL or 0.6 - 0.7 K/mcL (benign ethnic neutropenia) (mild), 1.0 - <1.5 K/mcL or 0.4 - 0.5 K/mcL (benign ethnic neutropenia) (moderate), <1.0 K/mcL or <0.4 K/mcL (benign ethnic neutropenia) (severe). If baseline clinical labs fell within mild range, then a laboratory AE was reported only if the value changed such that it fell into moderate range or higher when subsequent safety laboratory testing was done.

Safety Population: includes all participants who received at least one study vaccination

Thresholds for adverse events were considered as 50 - 123 unit/L (mild), 124 - 245 unit/L (moderate), >245 unit/L (severe). If baseline clinical labs fell within mild range, then a laboratory AE was reported only if the value changed such that it fell into moderate range or higher when subsequent safety laboratory testing was done.

Safety Population: includes all participants who received at least one study vaccination

Thresholds for adverse events were considered as creatinine 0.81 - 1.70 mg/dL (female) or 1.11 - 1.70 mg/dL (male) (mild), 1.71 - 2.00 mg/dL (moderate), >2.00 mg/dL (severe). If baseline clinical labs fell within mild range, then a laboratory AE was reported only if the value changed such that it fell into moderate range or higher when subsequent safety laboratory testing was done.

Safety Population: includes all participants who received at least one study vaccination

Thresholds for adverse events were considered as sodium 130 - 135 mmol/L or 146 - 150 mmol/L (mild), 123 - 129 mmol/L or 151 - 157 mmol/L (moderate), <123 mmol/L or >157 mmol/L (severe). If baseline clinical labs fell within mild range, then a laboratory AE was reported only if the value changed such that it fell into moderate range or higher when subsequent safety laboratory testing was done.

Safety Population: includes all participants who received at least one study vaccination

Thresholds for adverse events were considered as potassium 3.0 - 3.4 mmol/L or 5.2 - 6.0 mmol/L (mild), 2.5 - 2.9 mmol/L or 6.1 - 6.5 mmol/L (moderate), <2.5 mmol/L or >6.5 mmol/L (severe). If baseline clinical labs fell within mild range, then a laboratory AE was reported only if the value changed such that it fell into moderate range or higher when subsequent safety laboratory testing was done.

Safety Population: includes all participants who received at least one study vaccination

Thresholds for adverse events were considered as BUN 24 - 26 mg/dL (mild), 27 - 31 mg/dL (moderate), >31 mg/dL (severe). If baseline clinical labs fell within mild range, then a laboratory AE was reported only if the value changed such that it fell into moderate range or higher when subsequent safety laboratory testing was done.

Safety Population: includes all participants who received at least one study vaccination

Local reactogenicity solicited on memory aid include pain; tenderness; pruritus (itch); erythema (redness), induration (hardness/swelling), and ecchymosis (bruising) (functional and measurement). Thresholds for severity were pain: aware, no interference with activity, no pain med (mild), aware, interferes with activity or requires repeated use of a non-narcotic pain reliever for >24 hr (moderate), aware, prevents activity or requires prescription med use (severe); tenderness: area surrounding injection hurts when touched or with arm motion, no interference with daily activity (mild), hurts when touched or with arm motion, interferes with activity (moderate), hurts when touched or with arm motion and prevents activity (severe); functional erythema, induration, ecchymosis, and pruritus: no activity interference (mild), interferes with activity (moderate), prevents activity (severe); erythema, induration, and ecchymosis (measurement): <20mm (mild), 20 - 50mm (moderate), >50mm (severe).

Safety Population: includes all participants who received at least one study vaccination. All participants in all Study Arms received the same product (ChAd3-EBO-Z) at Day 1.

Local reactogenicity solicited on memory aid include pain; tenderness; pruritus (itch); erythema (redness), induration (hardness/swelling), and ecchymosis (bruising) (functional and measurement). Thresholds for severity grading were pain: aware, no interference with activity, no pain med (mild), aware, interferes with activity or requires repeated use of a non-narcotic pain reliever for >24hr (moderate), aware, prevents activity or requires prescription med use (severe); tenderness: area surrounding injection hurts when touched or with arm motion, no interference with daily activity (mild), hurts when touched or with arm motion, interferes with activity (moderate), hurts when touched or with arm motion, prevents activity (severe); functional erythema, induration, ecchymosis, and pruritus: no activity interference (mild), interferes with activity (moderate), prevents activity (severe); erythema, induration, and ecchymosis (measurement): <20mm (mild), 20-50mm (moderate), >50mm (severe).

Safety Population Subset: includes all participants who received the first and second study vaccination

Local reactogenicity solicited on memory aid include pain; tenderness; pruritus (itch); erythema (redness), induration (hardness/swelling), and ecchymosis (bruising) (functional and measurement). Thresholds for severity grading were pain: aware, no interference with activity, no pain med (mild), aware, interferes with activity or requires repeated use of a non-narcotic pain reliever for >24hr (moderate), aware, prevents activity or requires prescription med use (severe); tenderness: area surrounding injection hurts when touched or with arm motion, no interference with daily activity (mild), hurts when touched or with arm motion, interferes with activity (moderate), hurts when touched or with arm motion, prevents activity (severe); functional erythema, induration, ecchymosis, and pruritus: no activity interference (mild), interferes with activity (moderate), prevents activity (severe); erythema, induration, and ecchymosis (measurement): <20mm (mild), 20-50mm (moderate), >50mm (severe).

Safety Population: includes all participants who received at least one study vaccination.

Systemic reactogenicity solicited on memory aid included feverishness (chills/shivering/sweating), malaise (general unwell feeling), fatigue (tiredness), myalgia (body aches/muscular pain not at injection site), headache, nausea, loss of appetite, and elevated oral temperature. Thresholds for severity include feverishness, malaise, fatigue, myalgia, nausea, and loss of appetite: Noticeable but does not interfere with daily activity (Mild), Interferes with daily activity (Moderate), Significant interference, prevents daily activity (Severe); headache: Noticeable but does not interfere with daily activity (Mild), Any use of pain reliever or interferes with daily activity (Moderate), Significant interference, prevents daily activity, or requires any use of a prescription medication (Severe); elevated oral temperature: 37.8°C - 38.4°C or 100.00°F - 101.1°F (Mild), 38.5°C - 38.9°C or 101.2°F - 102.0°F (Moderate), >38.9°C or >102.0°F (Severe).

Safety Population: includes all participants who received at least one study vaccination. All participants in all Study Arms received the same product (ChAd3-EBO-Z) at Day 1.

Systemic reactogenicity solicited on memory aid included feverishness (chills/shivering/sweating), malaise (general unwell feeling), fatigue (tiredness), myalgia (body aches/muscular pain not at injection site), headache, nausea, loss of appetite, and elevated oral temperature. Thresholds for severity include feverishness, malaise, fatigue, myalgia, nausea, and loss of appetite: Noticeable but does not interfere with daily activity (Mild), Interferes with daily activity (Moderate), Significant interference, prevents daily activity (Severe); headache: Noticeable but does not interfere with daily activity (Mild), Any use of pain reliever or interferes with daily activity (Moderate), Significant interference, prevents daily activity, or requires any use of a prescription medication (Severe); elevated oral temperature: 37.8°C - 38.4°C or 100.00°F - 101.1°F (Mild), 38.5°C - 38.9°C or 101.2°F - 102.0°F (Moderate), >38.9°C or >102.0°F (Severe).

Safety Population Subset: includes all participants who received the first and second study vaccination

Systemic reactogenicity solicited on memory aid included feverishness (chills/shivering/sweating), malaise (general unwell feeling), fatigue (tiredness), myalgia (body aches/muscular pain not at injection site), headache, nausea, loss of appetite, and elevated oral temperature. Thresholds for severity include feverishness, malaise, fatigue, myalgia, nausea, and loss of appetite: Noticeable but does not interfere with daily activity (Mild), Interferes with daily activity (Moderate), Significant interference, prevents daily activity (Severe); headache: Noticeable but does not interfere with daily activity (Mild), Any use of pain reliever or interferes with daily activity (Moderate), Significant interference, prevents daily activity, or requires any use of a prescription medication (Severe); elevated oral temperature: 37.8°C - 38.4°C or 100.00°F - 101.1°F (Mild), 38.5°C - 38.9°C or 101.2°F - 102.0°F (Moderate), >38.9°C or >102.0°F (Severe).

Safety Population: includes all participants who received at least one study vaccination.

Vaccine-related unsolicited AEs include any untoward medical occurrence in a participant for which there is evidence to suggest a causal relationship between the study product and the adverse event. Thresholds for severity include events require minimal or no treatment and do not interfere with the subject's daily activities (mild), events result in a low level of inconvenience or concern with therapeutic measures and may cause some interference with functioning and daily activities (moderate), and events interrupt the subject's daily activities and may require systemic drug therapy or other treatment and are usually incapacitating (severe). Participants are counted once per preferred term and are summarized according to their highest severity. No severe events were reported.

Safety Population: includes all participants who received at least one study vaccination

The endpoint assessed antibodies against Ebola virus (EBOV) glycoproteins (GP) using an enzyme-linked immunosorbent assay (anti-EBOV GP ELISA). Venous blood samples for serum were used for this assay. Geometric mean fold rise (GMFR) compared to baseline (Day 1) was calculated for each study arm.

ITT Population: includes all participants who received at least one study vaccination and contributed both pre- and at least one post-study vaccination blood samples for immunogenicity testing for which valid results were reported

The endpoint assessed antibodies against Ebola virus (EBOV) glycoproteins (GP) using an enzyme-linked immunosorbent assay (anti-EBOV GP ELISA). Venous blood samples for serum were used for this assay. Geometric mean fold rise (GMFR) compared to baseline (Day 1) was calculated for each study arm.

Per Protocol population includes all participants who received at least one study vaccination, contributed both pre- and at least one post-study vaccination blood samples for immunogenicity testing for which valid results were reported, were eligible at baseline and have no major protocol deviations.

The endpoint assessed antibodies against Ebola virus (EBOV) glycoproteins (GP) using an enzyme-linked immunosorbent assay (anti-EBOV GP ELISA). Venous blood samples for serum were used for this assay. Geometric Mean Titer (GMT) was calculated for each study arm.

ITT Population: includes all participants who received at least one study vaccination and contributed both pre- and at least one post-study vaccination blood samples for immunogenicity testing for which valid results were reported

The endpoint assessed antibodies against Ebola virus (EBOV) glycoproteins (GP) using an enzyme-linked immunosorbent assay (anti-EBOV GP ELISA). Venous blood samples for serum were used for this assay. Geometric Mean Titer (GMT) was calculated for each study arm.

Per Protocol population includes all participants who received at least one study vaccination, contributed both pre- and at least one post-study vaccination blood samples for immunogenicity testing for which valid results were reported, were eligible at baseline and have no major protocol deviations.

The endpoint assessed antibodies against Ebola virus (EBOV) glycoproteins (GP) using an enzyme-linked immunosorbent assay (anti-EBOV GP ELISA). Venous blood samples for serum were used for this assay. Seroconversion was calculated for each study arm and was defined as anti-EBOV GP ELISA titer > 50 if baseline (Day 1) titer = 50 or fold rise > 4 as compared to baseline if baseline titer > 50.

ITT Population: includes all participants who received at least one study vaccination and contributed both pre- and at least one post-study vaccination blood samples for immunogenicity testing for which valid results were reported

The endpoint assessed antibodies against Ebola virus (EBOV) glycoproteins (GP) using an enzyme-linked immunosorbent assay (anti-EBOV GP ELISA). Venous blood samples for serum were used for this assay. Seroconversion was calculated for each study arm and was defined as anti-EBOV GP ELISA titer > 50 if baseline (Day 1) titer = 50 or fold rise > 4 as compared to baseline if baseline titer > 50.

Per Protocol population includes all participants who received at least one study vaccination, contributed both pre- and at least one post-study vaccination blood samples for immunogenicity testing for which valid results were reported, were eligible at baseline and have no major protocol deviations.

ChAd3-EBO-Z (2 x 10^11 virus particles (vp)) intramuscularly into the deltoid on Day 1 and ChAd3-EBO-Z (2 x 10^11 vp) intramuscularly into the opposite arm on Day 8.

ChAd3-EBO-Z (2 x 10^11 virus particles (vp)) intramuscularly into the deltoid on Day 1 and MVA-BN-Filo (1 x 10^8 Infectious Units (IU)) intramuscularly into the opposite arm on Day 8.