The objective of the clinical study is to evaluate the tolerability, safety, immunogenicity and prophylactic efficacy of the EpiVacCorona vaccine in volunteers aged 18 and above.

The study tasks are to:

• evaluate the safety of the EpiVacCorona vaccine when administered twice intramuscularly;
• evaluate the tolerability of the EpiVacCorona vaccine when administered twice intramuscularly;
• identify any adverse events to the administration of the EpiVacCorona vaccine;
• investigate the humoral immune response following two doses of the EpiVacCorona vaccine;
• investigate the cell-mediated immune response following two doses of the EpiVacCorona vaccine;
• evaluate the prophylactic efficacy of the EpiVacCorona vaccine when administered twice intramuscularly.

The study will screen a maximum of 4,929 volunteers of both sexes aged 18 and above, of which 3,000 volunteers who meet the inclusion criteria and do not have the exclusion criteria will be randomized:

• 2,250 volunteers who will be vaccinated with the EpiVacCorona vaccine, twice intramuscularly at a dose of 0.5 ml;
• 750 volunteers who will be vaccinated with a placebo, twice intramuscularly at a dose of 0.5 ml.

If volunteers drop out of the study, they will not be replaced. All volunteers will be followed up by an investigator physician for 6 months following the first vaccination in order to identify possible late adverse events. In case the volunteer has any late reactions, he/she will be invited to the clinic to correct his/her condition.

Inclusion Criteria:

1. Availability of a signed and dated informed consent of the volunteer to participate in a clinical trial, prior to any of the study procedures.
2. Volunteers (men and women) above the age of 18 years with stable indicators of basic vital functions.
3. Ability to attend all scheduled visits and all planned procedures and examinations.
4. Consent of volunteers to use effective contraceptive methods throughout the study, including the observation period for possible post-vaccination reactions.

Exclusion Criteria:

1. History of severe acute respiratory syndrome (SARS) or Middle East respiratory syndrome (MERS) or another coronavirus infection (HCoV-229E, HCOV-OC43, HCoV-NL63, HCoV-HKU1).
2. History of exposure to confirmed or suspected cases of SARS-CoV-2 infection within 1 month prior to randomization.
3. Positive for IgM or IgG to SARS-CoV-2 as detected during screening.
4. Positive PCR test for SARS-CoV-2 as detected during screening.
5. Clinically and laboratory (according to PCR data) confirmed disease caused by SARS-CoV-2 coronavirus, at the moment or in the past.
6. Serious post-vaccination reaction (body temperature above 40 °C , hyperemia or edema greater than 8 cm in diameter) or complication (collapse or shock-like state that developed within 48 hours after vaccination; convulsions, with or without of a febrile state) to a previous vaccination in the past.
7. Aggravated allergic history (anaphylactic shock, Quincke's edema, polymorphic exudative eczema, atopy, history of serum disease, history of hypersensitivity or allergic reactions to the administration of any vaccines, any known allergic reactions to vaccine components, etc.).
8. Hypersensitivity to any component of the product, allergy to vaccine components.
9. History of vaccination with any vaccine within one month prior to randomization.
10. Previous vaccination with rabies vaccines less than 2 months prior to randomization, or planned vaccination with rabies vaccines within 1 month after immunization with the vaccine under study.
11. Pregnancy or breastfeeding.
12. The military.
13. Persons in custody in detention facilities and those serving sentences in correctional facilities.
14. Children under the age of 18.
15. History of any acute respiratory illness less than 3 months prior to randomization.
16. Acute infectious or non-infectious diseases, exacerbation of chronic diseases less than 4 weeks prior to randomization.
17. History of tuberculosis (pulmonary and extrapulmonary), cancer, autoimmune diseases, skin diseases.
18. Long-term use (more than 14 days) of immunosuppressants, systemic glucocorticosteroids or immunomodulatory drugs within 6 months prior to randomization.
19. Use of immunoglobulin drugs or blood products within 3 months prior to randomization.
20. Chronic diseases of the cardiovascular, bronchopulmonary, endocrine systems, gastrointestinal tract, liver, kidneys, blood, disease of the endocrine system in the exacerbation phase or that in the decompensation phase in the past or as detected during laboratory and imaging examination.
21. History of surgery within 6 months prior to randomization.
22. Participation in other clinical trials less than 3 months prior to randomization.
23. Persons with alcohol or drug abuse (medications or narcotics). Use of more than 10 units of alcohol per week (1 unit of alcohol is equivalent to ½ liter of beer, or 200 ml of wine or 50 ml of alcohol) or history of alcoholism, narcomania or drug (medication) abuse.
24. Mental illness or neurasthenia.
25. Positive test for HIV, viral hepatitis B and C, or syphilis.
26. Premenopausal women (last menstrual period ≤ 1 year prior to signing the informed consent) who are not surgically sterile and women who have reproductive potential but do not use or plan to use approved birth control products throughout the study nor they agree to a urine pregnancy test while participating in the study.
27. Serious concomitant diseases or pathological conditions not listed above, which, according to the investigator's opinion, could complicate the assessment of the study results, including any pathological deviations from the age norms and laboratory norms of blood and urine parameters, clinically significant in the investigator's opinion.

And:

1. The investigator's decision to exclude the volunteer for the benefit of the volunteer.
2. False inclusion (violation of inclusion or non-inclusion criteria) or the appearance of non-inclusion criteria during the study.
3. The decision of the investigator or the Sponsor to exclude the volunteer from the study due to a clinically significant deviation from the protocol/violation of the protocol.
4. Any undesirable phenomenon requiring the appointment of drugs not authorized by the protocol of this study.
5. Volunteer's desire to complete the study early for any reason.
6. Volunteer's failure to show up for a scheduled visit without the warning the investigator or loss of communication with the volunteer.
7. Positive urine drug test and / or alcohol breath test during the visit.