Phase 1, safety, immunogenicity and dose finding for two strengths of 0.5 × 10^6 and 2.5 × 10^6 (TCID50) inactivated SARS-CoV-2 vaccine FAKHRAVAC (MIVAC) injected in two schedules of two doses, 2 and 3 weeks apart in healthy adults aged 18-55 years: a randomized, double blind, placebo controlled, clinical trial

Inclusion criteria:

Iranian citizenship, and residence at a distance of 40-50 km from the study setting The ability of participants to study and understand informed consent, preferably educational level of high school and higher Ages 18 to 55 years Body mass index between 18 and 35 kg/m2 Complete health based on clinical and laboratory conditions Temperature less than or equal to 37.2°C sublingually based on electronic thermometer Negative IgG and IgM antibody titers against COVID-19 N antigen Negative RT-PCR test to detect COVID-19 Negative ELISA test for anti-HIV IgG Heart rate between 60 and 100 Systolic blood pressure between 90 and 140 mm Hg, diastolic blood pressure between 60 and 90 mm Hg Signing informed consent Accepting commitments to reduce the risk of COVID-19 infection No pregnancy Negative pregnancy test for β-hCG on the day of screening and the day of vaccination The use of at least one safe method of contraception (condoms, oral contraceptive pills, IUD, Norplant capsule) for women of reproductive age 18 to 49 years Willingness to continue using at least one safe method of contraception (condoms, oral contraceptive pills, IUD, Norplant capsule) for women of reproductive age 18 to 49 years up to three months after completion of the vaccination period Participants in the clinical trial should refrain from donating blood or plasma from the time of the first vaccination until three months after the last vaccination. Failure to participate in another trial during the present study Expressing the readiness of the person to remain among the people monitored in the study for the entire study period until the end of the research process within 14 months The use of one of the safest methods of contraception by married men up to three months after the last dose of vaccine

Exclusion criteria:

History (at the time of referral) of any acute or chronic symptomatic disease requiring ongoing internal care or surgery Belonging to medical staff or health care workers Breastfeeding History of receiving any vaccine (whether investigational or non-investigational) within 30 days prior to screening History of receiving other investigational drugs during the last 60 days (before the start of the present clinical trial) History of receiving blood or any blood product or immunoglobulin within three months before screening History of Immunodeficiency disorders (suspected and definite) History of long-term use of immunosuppressive drugs (more than 14 consecutive days) within four months prior to screening History of long-term use (more than 14 consecutive days) of systemic corticosteroids (equivalent to 10 mg or more daily prednisolone) or (high-dose inhaled steroids (more than 800 µg/day of beclomethasone dipropionate or equivalent) within four months prior to screening (excluding topical steroids) History of allergic diseases such as angioedema or anaphylaxis History of any known allergy to the drug or vaccine carriers (whether alum or albumin) History of known allergy to eggs History of autoimmune diseases Chemotherapy or radiotherapy in the last 5 years History of cancer in the last 5 years History of serious psychiatric illnesses History of blood disorders (dyscrasia, coagulation disorders, platelet deficiency or disorder, deficiency of blood factors) History of chronic obstructive pulmonary disease such as asthma, ischemic heart disease definitively diagnosed by a specialist History of ischemic heart disease treated by a physician or history of cardiac interventions by a physician History of hypertension treated by a physician History of diabetes treated by a physician History of congenital anomalies, growth retardation, genetic defects or severe malnutrition Individual and family history of chronic neurological diseases (including seizures and epilepsy) History of thyroid disease or Thyroidectomy Any history of substance or alcohol abuse in the past 2 years Any defect in the results of hematology or biochemical tests performed at the time of screening History of confirmed COVID-19 Acute febrile illness at the time of vaccination History of allergy to acetaminophen History of acute or chronic hepatitis B and C History of pulmonary or extrapulmonary tuberculosis or receiving antituberculous agents Taking prophylactic antitubercular drugs History of syncope during injection or blood drawing Splenectomy for any reason or history of abnormal spleen function Any close contact with a person with confirmed COVID-19 for a maximum of two weeks before the day of receiving the first vaccine dose Previous history of diseases such as SARS and MERS Ineligibility to participate in a clinical trial for any reason at the discretion of the researchers Employment as military service in the subdivisions of the Armed Forces

Target sample size: 135

Actual sample size reached: 135