Safety and Immunogenicity of ChulaCov19 BNA159 mRNA Vaccine

This is a phase 1 study that will evaluate the safety and immunogenicity of ChulaCov19 BNA159 mRNA vaccine in healthy adults.

ChulaCov19 BNA159 mRNA vaccine is the lipid nanoparticles (LNPs)-encapsulated mRNA-based ChulaCov19 vaccine developed by Chula VRC and manufactured by BioNet Asia, Thailand for the active immunisation of healthy adults against coronavirus disease 2019 (COVID-19). This is a phase 1 study that will evaluate the safety and immunogenicity of ChulaCov19 BNA159 mRNA vaccine in healthy adults. This study will be conducted in 2 study centers, open-label , dose finding, first in human (FIH) study conducted in healthy participants. There are two groups. One group will receive 25 ug of ChulaCov19 BNA159 mRNA vaccine and the other group will receive 50 ug of ChulaCov19 BNA159 mRNA vaccine. Each group will have 12 participants. Intramuscular injection of the investigational vaccine at the assigned dose, will be administered 21 days apart, on Day 1 and Day 22 ( ±3) .

Eligibility Criteria:
Inclusion Criteria:

1. Male or female participants between the ages of 18 and 60 years, inclusive, at enrolment
2. Women of child-bearing potential (WOCBP) may be enrolled in the study if the participant fulfils all the following criteria:

   1. Has a negative urine-based pregnancy test at screening and on the day of the first dose (Day1) and second dose (Day22)
   2. Must practice true abstinence or, if engaged in sexual relations with a male, they must agree to use highly effective (failure rate of \< 1% per year when used consistently and correctly), double-barrier contraceptive measures\* from screening and for a period of at least 60 days after the last dose of investigational vaccine.
   3. Is not currently breastfeeding.
3. Women of non-child-bearing potential may be enrolled in the study if the participant meet one of these following criteria:

   d. Postmenopausal (defined as having a history of amenorrhea of at least one year), or e. History of amenorrhea is less than one year, must have an FSH level \> 40 milli-international units per milliliter (mIU/mL), or f. Have a documented status of being surgically sterile (hysterectomy, bilateral oophorectomy, or tubal ligation/salpingectomy).
4. Males must be surgically sterile (\>30 days since vasectomy with no viable sperm), practice true abstinence or, if engaged in sexual relations with a female of child-bearing potential, the participants and their partner must use an acceptable, highly effective, double-barrier contraceptive method\* from Screening and for a period of at least 60 days after the last dose of investigational vaccine.

   \* The PI is to assess the adequacy of methods of contraception on a case-by-case basis. These criteria do not apply if the participants are in a same-sex relationship.

   Type of Participant and Disease Characteristics:
5. Participants must be able to communicate effectively with study personnel and agree to comply with the study procedures.
6. Capable to provide written informed consent.
7. Healthy participants who are determined by medical history, physical examination (if required), and clinical judgment of the investigator to be eligible for inclusion in the study.
8. Participants must have haematology, clinical chemistry, coagulation and urinalysis test results that are not deviating from the normal reference range by age and gender to a clinically relevant extent at Screening.

   Exclusion Criteria:
9. Presence of clinically significant medical history, unstable chronic or acute disease, or physical, or laboratory findings that, in the opinion of the PI may potentially increase the expected risk of exposure to the investigational vaccine, compromise the safety of the participant, or interfere with any aspect of study conduct or interpretation of results. This will include any thrombocytopenia or bleeding disorder contraindicating IM vaccination.
10. Known infection with human immunodeficiency virus (HIV), hepatitis C virus (HCV), or hepatitis B virus (HBV).
11. History of severe adverse reaction associated with a vaccine and/or severe allergic reaction (eg, anaphylaxis) to any component of the study intervention(s).
12. Participant has previously participated in an investigational study involving LNPs (a component of the investigational vaccine assessed in this trial).
13. Previous clinical (based on COVID-19 symptoms/signs alone, if a SARS-CoV-2 NAAT result was not available) or microbiological (based on COVID-19 symptoms/signs and a positive SARS-CoV-2 NAAT result) diagnosis of COVID-19.
14. Close contact with anyone known to have SARS-CoV-2 infection within 10 days prior to vaccine administration.
15. Individuals at high risk for severe COVID-19, including those with any of the following risk factors:

    * Uncontrolled hypertension
    * Diabetes mellitus
    * Cardiovascular disease
    * Chronic pulmonary disease
    * Asthma
    * Chronic liver disease
    * Stage 3 or worse chronic kidney disease (glomerular filtration rate \<60 mL/min/1.73 m2)
    * BMI \>30 kg/m2
    * Individuals with a history of autoimmune disease

    Prior/Concomitant Therapy:
16. Previous vaccination with any coronavirus vaccine at any time prior to the study or planned receipt of any other licensed or experimental SARS-CoV-2 vaccine within 50 days of receipt of the first study vaccination.
17. Receipt of medications intended to prevent COVID-19.
18. Chronic use (more than 14 continuous days) of or anticipated need to use, within the next 6 months, of any medications that may be associated with impaired immune responsiveness or with immunosuppression.
19. Receipt of immunoglobulins or blood products within 3 months of first vaccination.

    Diagnostic Assessments:
20. Positive on SAR-CoV-2 -RBD and/or -N antibody IgG/IgM at screening visit
21. Positive test for HIV, hepatitis B surface antigen (HBsAg) or hepatitis C virus antibodies (HCV Abs) at the screening visit.

    Other Exclusions:
22. Is a participant at high risk of SARS-CoV-2 exposure in the opinion of the PI (e.g., healthcare workers, active health care workers with direct patient contact, emergency response personnel).
23. Participation in other studies involving study intervention within 28 days prior to study entry and/or during study participation.