IRCT20201202049567N3 IRCT 2021-03-13 Shifa Pharmed Industrial Co. Evaluate the safety and efficacy of COVID-19 inactivated vaccine A double-blind, randomized, placebo-controlled Phase II/III Clinical trial to evaluate the safety and efficacy of COVID-19 inactivated vaccine (Shifa-Pharmed) in a population aged 18 to 75 years 2021-03-14 anticipated 20000 Complete https://irct.ir/trial/54881 interventional Randomization: Randomized, Blinding: Double blinded, Placebo: Used, Assignment: Parallel, Purpose: Prevention, Randomization description: Phase 2: For less than 50 years participants, a randomized list with a length of 200 will be produced. Each sequence has a ratio of 4:1 vaccine to placebo and 160 participants will receive the active vaccine and 40 participants will receive a placebo. Sequences are generated using sealedenvelope.com by the block size of 5 (40 blocks) which has four interventions and one placebo in each block. For 51 to 75 years participants, the randomization sequence will be separately generated for 80 participants (64 active intervention and 16 placeboes) in a similar way. Phase 3: in this stage, stratified block randomization will be performed based on six cities and two age groups (<50 years and 51-75 years). Each stratum consists of blocks of size of 3 and a ratio of 2:1 (vaccine to placebo). All random allocation processes will be performed by an interactive web response system (IWRS), Blinding description: Every dose of vaccine is packaged separately and has a unique identification number. Vials and boxes of vaccine and placebo have a similar shape and packaging that results in blinding for participants, investigators, and outcome assessors. 2-3 COVID-19 disease. Intervention 1: Intervention group 2: 5 micrograms of antigen protein (Shifa Pharmed Co.) on days 0 and 28, which is received intramuscularly (deltoid muscle). Intervention 2: Control group: The placebo group will receive only aluminum hydroxide adjuvant in the form of deltoid intramuscular injection on days 0 and 28. Placebo is similar to the active vaccine in shape and volume. Undecided - It is not yet known if there will be a plan to make this available Justification or reason for indecision in sharing IPD is It will be decided based on the regulatory considerations