A Phase 3, Randomized, Double-blind, Placebo-controlled, Multicenter Study to Evaluate the Efficacy, Safety, Immunogenicity,and Lot-to-Lot consistency of BBV152, a Whole virion Inactivated Vaccine in Adults greater than or equal to 18 Years of Age

INTERVENTION: Intervention1: BBV152B: 6 µg antigen with Algel‐IMDG: Whole‐Virion Inactivated SARS‐CoV‐2 vaccine (BBV152) will be administered as a two dose intramuscular injection 28 days apart. Control Intervention1: Placebo (Phosphate buffered saline with Algel): Phosphate buffered saline with Alum (without antigen) will be used as the control.will be administered as a two dose intramuscular injection 28 days apart. CONDITION: PRIMARY OUTCOME: To evaluate the efficacy of BBV152B to prevent symptomatic COVID‐19(Virologically confirmed‐(RT‐PCR positive) which include any participant who meets the Case Definitions for Symptomatic Endpoint and Severe Symptomatic COVID‐19Timepoint: Day 42 to Month 12 INCLUSION CRITERIA: 1. Ability to provide written informed consent and availability to fulfill the study requirements. 2. Participants of either gender of aged 18 years and above. 3. Participants with good general health as determined by the discretion of the investigator, or participants with stable medical conditions. A stable medical condition is defined as a disease not requiring significant change in therapy or hospitalization or worsening disease during the 3 months before enrolment. 4. For a female participant of child‐bearing potential, planning to avoid becoming pregnant (use of an effective method of contraception or abstinence) from the time of study enrolment until at least eight weeks after the last vaccination. 5. Male subjects of reproductive potential: Use of condoms to ensure effective contraception with the female partner and to refrain from sperm donation from first vaccination until at least 3 months after the last vaccination. 6. Agrees not to participate in anoth SECONDARY OUTCOME: EFFICACY:To evaluate the efficacy of BBV152B to prevent‐ ; 1. COVID‐19 based on the case definition for the secondary efficacy symptomatic endpoint. ; 2.COVID‐19‐Virologically confirmed (RT‐PCR positive) severe cases of COVID19. ; 3.Any severity of COVID‐19 by age. ; 4.Asymptomatic COVID‐19. ; 5.COVID‐19 regardless of symptomatology or severity ; 6.COVID‐19 related deaths ; 7.Symptomatic COVID‐19, regardless of the previous infectionTimepoint: 1.Day 42 to Month 12 ; 2.Day 42 to Month 12. ; 3.Day 42 to Month 12 ; 4.Month 2 to Month 12 ; 5.Day 42 to Month 12 ; 6.Day 42 to Month 12 ; 7.Day 42 to Month 12 IMMUNOGENECITY ; To evaluate the immunogenicity of BBV152B ; 1.Geometric Mean Titer (GMT) of SARS‐CoV‐2 Specific Neutralizing Antibody (nAb) ; 2.Geometric Mean Fold Rise (GMFR) of SARS‐CoV‐2 Neutralizing Antibody (nAb). ; 3.Geometric Mean Titer (GMT) of SARS‐CoV‐2 S1 protein‐specific Binding Antibody (bAb). ; 4.Lot‐to‐Lot consistency will be assessed based on the neutralizing titer of the three consistent lots used in the trialTimepoint: 1.Month 0 to Month 12 ; 2.Month 0 to Month 12 ; 3.Month 0 to Month 12 ; 4.Month 0 to Month 2 SAFETY ; To assess the safety of BBV152B 1.Serious Adverse Events occurring at any time ; 2.Solicited local and systemic adverse events (AEs). ; 3.Unsolicited AEs occurring between the vaccination and 28 days after the final vaccination. ; 4.Immediate AEs with 30 minutes of vaccination ; 5. Medically attended adverse events (MAAEs) or AEs leading to withdrawal ; 6.The occurrence of enhanced respiratory disease episodes reported by participant/documented in hospital records 7.AE of Special interestTimepoint: 1.Throughout the study period ; 2.Within 7 days post each vaccination ; 3.Till 28 days post second dose vaccination ; 4. Within 30 minutes post each vaccination ; 5.Throughout the study period ; 6.Throughout the study period 7.Throughout the study period