A Phase I Study of PepGNP-ChikV in Healthy Volunteers

1. Healthy individuals aged ≥18 years to ≤60 years of age, inclusive at time of consent, who are not receiving any excluded concomitant medications as detailed in protocol

2. Informed consent form signed.

3. Determined to be eligible by the Investigator based on medical history, physical examination, and screening laboratory testing.

4. Women of childbearing potential are willing to use effective birth control method(s) for a minimum of 14 days prior to dosing through 90 days after last study vaccination.

5. Male participants with a partner of childbearing potential must agree to use a highly effective method of contraception (e.g. hormonal contraception, intrauterine device, or sterilization) and refrain from sperm donation during the study and for at least 6 months after the last dose of study drug.

1. Self-reported or documented history of laboratory-confirmed chikungunya or other mosquito-borne (arthropod) disease, such as Zika or dengue within 90 days prior to consent.

2. Travel in the previous 90 days to areas where exposure to flaviviruses such as Zika, dengue, West Nile Fever are common, as well as areas increasing in cases of chikungunya (refer to the following website: Chikungunya virus disease worldwide overview).

3. Self-reported or documented receipt of any chikungunya (alphavirus) or flavivirus vaccine (investigational or licensed) within 90 days prior to consent.

4. Receipt of any licensed vaccine, including COVID-19 vaccine, within the 28 days prior to consent or planned receipt within 90 days following last study vaccination (if unplanned circumstances subsequent to enrolment necessitate the receipt of a licensed vaccine e.g. tetanus and rabies, in unavoidable clinical settings, these should be documented in the source documents by the Investigator and not considered a protocol deviation. However, if the licensed vaccine is not urgently required, it should be delayed until at least 90 days following last study vaccination).

5. Known systemic hypersensitivity to any of the vaccine components (e.g. gold), or history of a life-threatening reaction to vaccines, or to a vaccine containing any of the same substances.

6. Acute illness according to Investigator judgment especially if febrile (≥38.0°C).

7. Screening laboratory testing reveals a toxicity grading higher than 1 according to Common Terminology Criteria for Adverse Events (CTCAE), Version 5.0 (NCI, 2017). If the Investigator suspects it to be an erroneous result, it can be repeated; the new result should be used for eligibility determination by the Investigator after documenting any clinical significance to any persistently abnormal result.

8. A positive SARS-CoV-2 polymerase chain reaction (PCR) or a positive rapid SARS-CoV-2 antigen test at Screening.

9. Women who are pregnant, or lactating,

10. Calculated body mass index (BMI) > 32.0 kg/m2.

11. Participation in another clinical study investigating a vaccine, drug, medical device, or medical procedure within 90 days or five half-lives, whichever is longer, prior to consent or planned participation in such a study during the period of this clinical study.

12. Receipt of immunoglobulins, blood or blood-derived products within 90 days prior to consent or planned receipt during the period of this chikungunya vaccine study.

13. Known or suspected congenital or acquired immunodeficiency or autoimmune disease; or receipt of immunosuppressive therapy such as anti-cancer chemotherapy or radiation therapy, within 90 days prior to consent; or long-term systemic corticosteroid therapy (prednisone or equivalent for more than 2 consecutive weeks within 90 days prior to consent).

14. Self-reported or documented Hepatitis surface antigen (HBsAg) positivity or antibody against human immunodeficiency virus (HIV), Hepatitis B core, or Hepatitis C. If HIV antibody positive, the participant is to be excluded if HIV is confirmed by further investigation. If Hepatitis C antibody is positive, a Hepatitis C viremia test may be ordered, and, if negative, the participant may continue to be considered for enrolment.

15. Thrombocytopenia (platelet count <150,000/mL) or any coagulation disorder considered clinically significant by the Investigator.

16. Chronic illness that, in the opinion of the investigator, is at a stage where it might interfere with study conduct or study completion.

17. Current alcohol abuse or drug addiction (reported or suspected).

18. Identified as an Investigator or employee of the Investigator or study center with direct involvement in the proposed study or identified as an immediate family member (i.e. parent, spouse, natural or adopted child) of the Investigator or employee with direct involvement in the proposed study. (i.e. in the employment of the clinical study site).