The purpose of this study is to investigate the safety and antibody (germ fighters) response of the experimental (investigational) vaccine against HCV when injected into the arm of healthy adults.

The Hepatitis C Virus (HCV) continues to be a significant public health threat, infecting 58 million people worldwide and over 250,000 Canadians. The virus disproportionately affects marginalized populations. It is a bloodborne virus that affects the liver and is most commonly spread through unsafe injection practices, sexual practices that lead to blood exposures, and unsafe health care (i.e., transfusion of contaminated blood and blood products). If left untreated, these infections progress to chronic hepatitis, liver cirrhosis (liver failure) and potentially hepatocellular carcinoma (liver cancer) or death. Current treatments for HCV include expensive drug combinations that can cure HCV in most but do not prevent reinfection if there is another exposure. At this time, there are no vaccines available to prevent HCV and the diseases that it causes.

Inclusion Criteria:

1. Able to understand the purpose and the procedures involved in this study and sign the informed consent form;
2. Non-pregnant individuals, 18-45 years of age inclusive;
3. Individuals must agree not to become pregnant during the trial. If they are capable of pregnancy and sexually active, they must use an effective method of birth control;
4. Non-smoker and in good general health, as determined by medical screening evaluation, performed by PI, or delegated sub-investigator no greater than 4 weeks (28 days) before the first dose in the form of medical history, clinical laboratory tests and physical examination;
5. Agrees to reside in the geographical area for next 12 months and not intending to travel outside of Canada for at least 14 days following each study vaccine administration;
6. Agree not to participate in any other clinical trial during the trial;
7. Agree not to donate blood for the duration of the trial;
8. Agree to restrain from intensive physical exercise i.e., exercise that varies significantly from an everyday exercise routine, 3 days before and after (± 3 days) administration of each dose, including each interim visit for blood sample collection;
9. Up to date on recommended seasonal vaccines (influenza and COVID-19) at the time of study enrolment.

Exclusion Criteria:

1. Presence of Hepatitis C antibody (HCV Ab);
2. Presence of significant acute infection requiring systemic antibiotic treatment within the 14 days prior to each product administration;
3. Pregnant or breast feeding (all individuals physiologically capable of pregnancy will have a negative pregnancy test result prior to each study product administered);
4. Past significant reaction following any previous vaccination;
5. History of hypersensitivity to any vaccine component;
6. Presence of acute infectious disease or fever (e.g., sub-lingual temperature 38.5°C) within the five days prior to study product administration;
7. Presence of current or suspected serious chronic diseases such as cardiac or autoimmune disease (HIV or other immunodeficiencies), insulin dependent diabetes, progressive neurological disease, severe malnutrition, acute or progressive hepatic disease, acute or progressive renal disease, psoriasis, rheumatoid arthritis, asthma, epilepsy or obsessive-compulsive disorder, skin carcinoma excluding non-spreadable skin cancers such as basal cell and squamous cell carcinoma;
8. Evidence and/or any history of leukaemia, lymphoma, or neoplasm;
9. Presence or suspicion of impaired immune system function. Currently receiving or having within the past three years received immunosuppressive therapy, including systemic steroids, ACTH or inhaled steroids in dosages that are associated with hypothalamic-pituitary-adrenal axis suppression, such as 1mg/kg/day of prednisone or its equivalent or chronic use of inhaled high potency corticosteroids [budesonide 800 µg per day or fluticasone 750 µg];
10. Received blood, blood products or a parenteral immunoglobulin preparation in the past 12 weeks;
11. Evidence of bleeding diathesis or any condition that may be associated with a prolonged bleeding time;
12. Known inherited genetic anomaly (known as cytogenic disorders) e.g., Down's syndrome;
13. Evidence of any condition that, in the opinion of the clinical investigator, might interfere with the evaluation of the study objectives or pose excessive risks to participants;
14. Clinically significant abnormal laboratory as assessed by the trial physician.

The first stage will be "open-label" where 3 participants will receive the AVIHepC1 vaccine to assess for safety dosing whereas, the second stage will be double-blinded where the remaining 24 participants will receive either the AVIHepC1 vaccine or a placebo (saline).