Safety, and Immunogenicity Study of the Recombinant Two-component COVID-19 Vaccine (CHO Cell)
Condition: COVID-19
MeSH terms: COVID-19
Study type: Interventional
Phase: Phase 2

Summary: 
      Part 1: Primary Vaccination in Adults Part 1 will evaluate the safety and immunogenicity of
      the recombinant two component COVID-19 vaccine (CHO cell) (ReCOV for short) in adults aged 18
      years and older, when administered as 2 intramuscular doses, 21 days apart.

      Part 2: Booster Vaccination in Adults Part 2 will evaluate the immunogenicity and safety and
      of one booster dose of ReCOV in adult participants who have received primary vaccination with
      2 doses of an inactivated COVID-19 vaccine (CoronaVac®). COMIRNATY®, an mRNA COVID-19 vaccine
      will be used as the active control.
    

Detailed description: 
      Part 1: Primary Vaccination in Adults Around 340 participants aged 18 years and older who do
      not have known COVID-19 or COVID-19 vaccination history will be randomized into ReCOV group
      (40 μg) or placebo group in a ratio of 2:1. Accordingly, around 227 participants will receive
      40 μg ReCOV and 113 participants will receive matching placebo, respectively. Participants
      will be stratified by age (18~59 years, ≥60 years) and status of SARS-CoV-2 antibody at
      baseline.

      After randomization, participants will enter into a double-blinded period (until all
      participants complete V6) and an open-label long-term follow-up period (after all
      participants complete V6 until end of the study).

      After all participants complete the visit at 7 days after the 2nd vaccination, the safety and
      reactogenicity data will be summarized by an independent statistic group, while the sponsor,
      investigators and all study participants will be kept blinded. The safety summary will be
      submitted to DSMB for review and recommendation on the initiation of Part 2.

      The primary analysis of Part 1 is planned after all participants complete the Visit 6 (V3 +
      28 days, +7 days) and are unblinded, to evaluate the safety and immunogenicity during the
      double-blinded period.

      The final analysis of Part 1 will be conducted after all participants of the ReCOV group
      complete the follow-up visit at 6 months after the 2nd vaccination, to evaluate the safety
      and immunogenicity during this study stage.

      Part 2: Booster Vaccination in Adults This study part will enroll participants who have
      received primary vaccination by an inactivated COVID-19 vaccine (CoronaVac®) within 3 to 12
      months (90~365 days). The mRNA COVID-19 vaccine, COMIRNATY ®, will be used as the active
      control. The immunogenicity induced by the booster vaccination of ReCOV (commercial batch,
      Lot# TC202205002) will be compared with that of COMIRNATY®. In addition, the immunogenicity
      of one dose booster of commercial batch ReCOV (Lot# TC202205002) will be compared with that
      of pilot batch ReCOV (Lot# HA202107009).

      About 588 participants will be enrolled into the study. Eligible participants will be 1:1:1
      randomized to receive 20 μg ReCOV (Lot# HA202107009), 20 μg ReCOV (Lot# TC202205002), or 30
      μg COMIRNATY®, stratified by age (18~59 years, ≥60 years) and the duration since the last
      primary vaccination (90~180 days, 181~365 days).

      All participants will be followed up for safety and reactogenicity. Participants will be
      observed for 30 minutes at study site after the vaccination. Before leaving the study site,
      participants will be given participant diaries to record solicited AEs within 7 days after
      dosing, and unsolicited AEs within 28 days after dosing. The occurrence of SAEs and AESIs
      will also be monitored till 6 months after the study vaccination.

      The interim analysis is planned after all participants complete the Visit 5 at 28 days after
      the dosing, to evaluate the immunogenicity and safety within this period.

      The final analysis will be conducted after all participants complete the follow-up visit at 6
      months post the booster vaccination, to evaluate the immunogenicity and safety.
    

Intervention name(s): Part1:Recombinant two-component COVID-19 vaccine (CHO cell); Part1: Placebo; Part2: Recombinant two-component COVID-19 vaccine (CHO cell); Part2: COVID-19 Vaccine, mRNA
Intervention type(s): Biological; Biological; Biological; Biological
Intervention description(s): 2 doses. Before reconstitution:Lyophilized powder for reconstitution in single-use vials; After reconstitution with BFA03 adjuvant: Milk-white solution with no visible foreign matter; Unite Does Strengths: 40ug/vial; Does Volume: 0.5ml/dose Routine of administration: Intramuscular (IM) injection; 2 doses. Before reconstitution: Lyophilized powder for reconstitution in single-use vials; After reconstitution with BFA03 adjuvant: Milk-white solution with no visible foreign matter; Unite Does Strengths: Not Applicable; Does Volume: 0.5ml/dose; Routine of administration: IM injection;; 1 dose.Before reconstitution:Lyophilized powder for reconstitution in single-use vials; After reconstitution with BFA03 adjuvant: Milk-white solution with no visible foreign matter; Unite Does Strengths: 40ug/vial; Does Volume: 0.5ml/dose Routine of administrati; 1 dose. Intramuscular injection, 30 μg/0.3 mL.
Other intervention name(s): Part1: ReCOV; Part2: ReCOV; Part2: COMIRNATY®
Intervention MeSH terms: Vaccines
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Part1: 2 arms Part2: 2 arms
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Prevention