Immunogenicity of Recombinant Vesicular Stomatitis Vaccine for Ebola-Zaire (rVSV[Delta]G-ZEBOV-GP) for Pre-Exposure Prophylaxis (PREP) in People at Potential Occupational Risk for Ebola Virus Exposure

Between 1994 and the present, there have been multiple Ebolavirus outbreaks affecting mostly
central Africa. However, the 2014/2015 West African outbreak significantly exceeds all
previous outbreaks in geographic range, number of individuals affected, and in disruption of
typical activities of civil society.

This protocol is a multi-center study to evaluate the durability of the immune response
following the open label administration of the investigational rVSVdeltaG-ZEBOV-GP vaccine
(V920) as pre-exposure prophylaxis for adults who have an occupational risk for potential
exposure to Ebola virus. The vaccine uses a live replicating vesicular stomatitis virus (VSV)
replacing the gene encoding the G envelope glycoprotein with the gene encoding the envelope
glycoprotein from the Zaire strain of Ebola (rVSVdeltaG-ZEBOV-GP also known as V920).

All subjects will receive a single dose of rVSVdeltaG-ZEBOV-GP (2 x 10^7 pfu) on Day 0. We
will collect adverse events after vaccination and at Month 1 and Month 19, serious adverse
events (SAE) for the duration of the study, and assess the immune response at Months 1, 3, 6,
12, 18, 19, 24, 30, and 36.

A single booster immunization with the same dose of study vaccine as the primary dose (2 x
10^7 pfu/mL) will be given to those randomized at month 18 to the booster arm of the trial.
However, if at any time during the observation period antibody levels fall below a predefined
seroprotective threshold (yet to be defined in parallel or newly planned studies), a booster
will be offered to those who have not previously received a booster injection.

-INCLUSION CRITERIA:

1. Adults age greater than equal to 18 years.

2. Signed informed consent for the trial.

3. At risk of occupational exposure to Ebola virus through laboratory, clinical contact,
or field work, in the judgment of the investigator.

4. Females of childbearing potential must be willing to use effective methods of
contraception, from at least 30 days prior to vaccination through 1 month following
vaccination/booster, which would include:

- oral contraceptives, either combined or progestogen alone

- injectable progestogen

- implants of etenogestrel or levonorgestrel

- oestrogenic vaginal ring

- percutaneous contraceptive patches

- intrauterine device or intrauterine system

- committed to abstinence from potentially reproductive sexual contact [i.e. will
NOT engage in heterosexual intercourse where both partners are capable of
reproduction]

- surgical sterilization

- male condom combined with a spermicide

5. All males must be willing to use effective methods of contraception for at least 1
month following vaccination/booster, which would include:

- surgical sterilization

- male condom combined with a spermicide

6. Willing to minimize blood and body fluid exposure to others for at least 14 days after
vaccination/booster. This includes:

- Use of effective barrier prophylaxis, such as latex condoms, during any sexual
interaction (regardless of childbearing status or sexual orientation)

- Avoiding the sharing of needles, razors, eating utensils, drinking from the same
cup, or toothbrushes

- Avoiding open-mouth kissing

- Use of universal precautions in the health-care setting

7. Agrees not to receive another investigational agent between vaccination and the Month
1 study visit (and booster and Month 19 study visit).

8. Willing to forgo blood donation for one year from vaccination/booster.

9. Willing to accept randomization (boost versus no boost) at month 18 visit.

EXCLUSION CRITERIA:

1. Any condition that would limit the ability of the participant to meet protocol
requirements or would place the participant at unreasonable risk. Examples include:

- Clinically significant medical condition, physical examination findings,
clinically significant abnormal laboratory results, or past medical history with
clinically significant implications for current health, per the investigator. A
clinically significant condition or process includes but is not limited to:

1. A process that would adversely affect the systemic immune response

2. A process that would require medication that might adversely affect the
systemic immune response

3. Any contraindication to repeated injections or blood draws

4. A condition that requires active medical intervention or monitoring to avert
grave danger to the participant s health or well-being during the study
period

5. A condition or process for which signs or symptoms could be confused with
reactions to vaccine

- Presence of any pre-existing illness or clinical history that, in the opinion of
the investigator, would place the participant at an unreasonably increased risk
through participation in this study. This includes but is not limited to:

1. Active malignancy

2. History of Guillain-Barr(SqrRoot)(Copyright) Syndrome

3. History of neurological disorder that may increase risk (history of
encephalitis, stroke, or seizure)

4. Active autoimmune disorder requiring systemic immunosuppressive treatment

- Any concomitant medication for which reported side effects or adverse events, in
the judgment of the investigator, may interfere with assessment of safety.

- Subjects who, in the judgment of the investigator, will be unlikely or unable to
comply with the requirements of this protocol.

2. Positive urine or serum pregnancy test

3. Women who are currently breast-feeding.

4. Known allergy to the components of the rVSV G-ZEBOV-GP vaccine (V920) vaccine product
(VSV, albumin, tris).

5. History of severe local or systemic reactions to any vaccination.

6. Received an investigational drug within 5 half-lives or 30 days, whichever is longer,
prior to vaccination (Day 0)/booster (Month 18).

7. Received licensed killed vaccines 14 days before vaccination (Day0)/booster (Month
18).

8. Received live virus vaccines within 30 days before, or intention to receive live virus
vaccines within 30 days following, vaccination (Day 0)/booster (Month 18).

9. Received immunoglobulins and/or any blood products within the 120 days preceding
vaccination (Day 0)/booster (Month 18).

10. Received allergy treatment with antigen injections within 30 days before vaccination
(Day 0)/booster (Month 18).Clinical evidence (e.g. oral temp >38 degrees Celsius,
systemic symptoms) of a systemic infection or other acute intercurrent illness at the
proposed time of vaccination (Day 0)/booster (Month 18).