A PhaseⅡ Study to Evaluate the Safety & Immunogenicity of SARS-CoV-2 Alpha/Beta/Delta/Omicron Variants COVID-19 Vaccine
Condition: COVID-19 Pandemic
MeSH terms: COVID-19
Study type: Interventional
Phase: Phase 2

Summary: 
      This study is a randomized, double-blind, placebo-controlled Phase II clinical trial to
      evaluate the safety and immunogenicity of SCTV01E in population of different ages who have
      been vaccinated against COVID-19. A total of 750 participants ≥3 years old who have received
      the recommended dose and immunization procedure of domestically approved COVID-19 vaccines
      will be enrolled, including 250 participants ≥18 years old (group A), 250 participants aged
      12-17 years old (group B), and 250 participants aged 3-11 years old (group C). The study will
      be carried out gradually according to the age of the participants from older to younger.
      Considering that SCTV01E in this study is the first clinical study in participants under 18
      years old, 15 sentinel participants will be assigned to group B and 30 sentinel participants
      will be assigned to group C (including 15 aged 6-11 years old and 15 aged 3-5 years old).

      The Primary end points are 1. The incidence and severity of solicited adverse events on days
      0-7 after inoculation with SCTV01E. 2. IgG total antibody concentrations (ELISA) against
      SARS-CoV-2 prototype strains and neutralizing antibodies titer (Live virus neutraliztion
      antibody test) against SARS-CoV-2 Omicron variant at 28 days post-vaccination.
    

Detailed description: 
      Firstly, 250 participants will be randomly enrolled in group A, among which the first 15
      participants will be observed for 7 days after receiving the study vaccine and assessed for
      safety by the DSMB. If the 15 participants do not meet the study suspension/termination
      criteria, 15 sentinel participants in group B will be enrolled. The sentinel participants in
      Group B will be observed for 7 days after receiving the study vaccine, and safety is assessed
      by the DSMB. If the sentinel participants in group B do not meet the study
      suspension/termination criteria, non-sentinel participants in Group B and 15 sentinel
      participants in Group C aged 6-11 years old will be enrolled at the same time. The 15
      sentinel participants aged 6-11 years in group C will be observed for 7 days after receiving
      the study vaccine and assessed for safety by the DSMB. If the study suspension/termination
      criteria are not met, non-sentinel participants aged 6-11 years old in group C and 15
      sentinel participants aged 3-5 years old in group C will be enrolled, and sentinel
      participants aged 3-5 years old in group C will be observed for 7 days after receiving the
      study vaccine. Safety will be assessed by the DSMB and non-sentinel participants aged 3-5
      years old in Group C will be enrolled if study suspension/termination criteria are not met in
      sentinel participants aged 3-5 years old.

      Participants in each group (including the first 15 participants in Group A and sentinel
      participants in groups B and C) will be randomly inoculated with either SCTV01E or placebo
      (normal saline) at a ratio of 4:1, i.e. 200 participants in each group will receive SCTV01E
      and 50 participants will receive placebo (normal saline).

      Randomized stratification factors for group A are age (18-59 years vs. ≥60 years), past
      COVID-19 vaccination status (completion of baseline immunization vs. Completion of booster
      immunization), the last type of COVID-19 vaccine received (inactivated vs. other vaccines),
      and the duration of prior Informed consent form (ICF) signing (6-12 months vs. 12-24 months);
      Randomized stratification factor for group B are past COVID-19 vaccination (completion of
      baseline immunization vs. Completion of booster immunization), type of COVID-19 vaccine last
      received (inactivated vs. other vaccines) and time since ICF last received (6-12 months vs.
      12-24 months); Random stratification factors for group C are age (3-5 years vs. 6-11 years),
      past COVID-19 vaccination (completion of baseline immunization vs. Completion of enhanced
      immunization), the last type of COVID-19 vaccine received (inactivated vs. other vaccines),
      and the duration of prior Informed consent form (ICF) signing (6-12 months vs. 12-24 months).
    

Intervention name(s): SCTV01E; Placebo (normal saline)
Intervention type(s): Biological; Biological
Intervention description(s): Participants will be vaccinated with SCTV01E on Day 0, and safety and immunogenicity will be monitored for 180 days after vaccination.; Participants will be vaccinated with Placebo (normal saline) on Day 0, and safety and immunogenicity will be monitored for 180 days after vaccination.
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Participants ≥3 years old who has received the recommended dose and immunization procedure of domestically approved COVID-19 vaccine, Participants in each group (including the first 15 participants in Group A and sentry participants in groups B and C) will be randomly inoculated with either SCTV01E or placebo (normal saline) according to 4:1, i.e. 200 participants in each group will receive SCTV01E and 50 participants will receive placebo (normal saline).
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Prevention
Keywords: COVID-19 Pandemic, Vaccine