A Phase IIb, Randomized, Double-Blinded Trial to Evaluate the Immunogenicity and Safety Study of the Booster Dose Using the High or Medium Dose of COVID- 19 Vaccine (Vero Cell), Inactivated in Healthy Adults Who Have Completed Two Doses of mRNA Vaccine in Hong Kong

Sinovac Research and Development Co., Ltd.1 site in 1 countryFebruary 10, 2022

ConditionsCOVID-19

Overview

Phase: Phase 2
Intervention: Not specified
Conditions: COVID-19
Sponsor: Sinovac Research and Development Co., Ltd.
Locations: 1
Primary Endpoint: Immunogenicity index-Geometric mean fold rise (GMFR) of neutralization antibody titre in the medium dose
Status: Withdrawn
Last Updated: 2 years ago

Overview Investigators Eligibility Criteria Outcomes Sites Similar Trials

Overview

Brief Summary

This is a randomized, double-blinded, Phase IIb clinical trial of COVID-19 vaccine (CoronaVac®) manufactured by Sinovac Research & Development Co., Ltd.The purpose of this study is to evaluate to evaluate the changes in immunogenicity before and after the booster vaccine using the high (1200 SU) or medium (600 SU) dose of COVID-19 Vaccine (Vero Cell), Inactivated.

Detailed Description

This is a randomized, double-blinded, Phase IIb clinical trial of 150 participants aged 18 years and above, who have completed two doses of mRNA COVID-19 vaccine as the primary vaccination for at least six months after the second dose. After enrollment, participants will be randomly assigned into two study arms at a ratio of 1:1 to receive a booster of one dose of medium-dose (600 SU) or one dose of high-dose (1200 SU) COVID-19 Vaccine.

Registry

clinicaltrials.gov

Start Date

February 10, 2022

End Date

March 10, 2022

Last Updated

2 years ago

Study Type

Interventional

Study Design

Parallel

Sex

All

Investigators

Sponsor

Sinovac Research and Development Co., Ltd.

Responsible Party

Sponsor

Eligibility Criteria

Inclusion Criteria

•Healthy adults aged 18 years and above, who have received two prior doses of mRNA COVID-19 vaccine (Comirnaty®, made by BioNTech/Pfizer) as the primary vaccination, with the second dose given at least 180 days prior to the day of booster vaccination in the present study;
•Evidence of a deep throat saliva (DTS) PCR negative for SARS-COV-2 within 24 hours before enrollment;
•Female participants who have a negative pregnancy test on the day of vaccination, and not currently breastfeeding;
•The participants are able to understand and sign the informed consent voluntarily;
•The participants are willing and able to comply with all schedule visits, sample collection,vaccine plan, and other study procedures;
•The participants must be willing to provide verifiable identification (in accordance with the local regulations), has means to be contacted and to contact the investigator during the study.

Exclusion Criteria

•History of confirmed or having evidence showing a current infection of SARS-CoV-2 prior to randomization;
•Any prior administration of another investigational coronavirus vaccine or current/planned simultaneous participation in another interventional study to prevent or treat COVID-19;
•Known allergy to vaccines or vaccine ingredients, and serious adverse reactions to vaccines, such as urticaria, dyspnea, angioneurotic edema;
•Serious chronic disease, serious cardiovascular disease, hypertension and diabetes that cannot be controlled by drugs, hepatorenal disease, malignant tumor, etc.;
•Acute central nervous system diseases such as encephalitis/myelitis, acute disseminating encephalomyelitis, and related disorders;
•Receipt of blood/plasma products or immunoglobulins in the past three months before vaccination in this study;
•Participation in other studies involving study intervention within 30 days prior to vaccination in this study;
•Receipt of attenuated live vaccines in the past fourteen days prior to vaccination in this study;
•Receipt of inactivated or subunit vaccines in the past seven days prior to vaccination in this study;
•Acute exacerbation or presentation of stable chronic diseases (including but not limited to asthma,migraine, gastrointestinal disorder, etc.);

Outcomes

Primary Outcomes

Immunogenicity index-Geometric mean fold rise (GMFR) of neutralization antibody titre in the medium dose

Time Frame: 28 days after the booster dose vaccination

Geometric mean fold rise (GMFR) of neutralization antibody titre from baseline to 28 days post the booster vaccine in the medium dose .

Immunogenicity index-Geometric mean fold rise (GMFR) of neutralization antibody titre in the high dose

Time Frame: 28 days after the booster dose vaccination

Geometric mean fold rise (GMFR) of neutralization antibody titre from baseline to 28 days post the booster vaccine in the high dose .

Secondary Outcomes

Immunogenicity index-GMT of neutralizing antibody in the high dose(3 months after the booster dose vaccination)
Immunogenicity index-Geometric mean of neutralizing antibody titer (GMT)in the medium dose(28 days after the booster dose vaccination)
Immunogenicity index-GMT of neutralizing antibody in the medium dose(3 months after the booster dose vaccination)
Safety index-Occurrence and relationship of SAEs(Within 12 months post booster vaccination)
Immunogenicity index-The seropositivity rate of neutralizing antibody in the medium dose(3 months after the booster dose vaccination)
Immunogenicity index-the GMT of neutralizing antibody in the high dose(6 months after the booster dose vaccination)
Immunogenicity index-the seropositivity rate of neutralizing antibody in the high dose(28 days after the booster dose vaccination)
Immunogenicity index-The seropositivity rate of neutralizing antibody in the high dose(3 months after the booster dose vaccination)
Immunogenicity index-The seropositivity rate in the high dose(6 months after the booster dose vaccination)
Immunogenicity index-The seropositivity rate in the medium dose(6 months after the booster dose vaccination)
Safety index-Occurrence and relationship of AESI(Within 12 months post booster vaccination)
Immunogenicity index-the seropositivity rate of neutralizing antibody in the medium dose(28 days after the booster dose vaccination)
Immunogenicity index-Geometric mean of neutralizing antibody titer (GMT) in the medium dose(28 days after the booster dose vaccination)
Immunogenicity index-the GMT of neutralizing antibody in the medium dose(6 months after the booster dose vaccination)
Safety index-Occurrence, intensity, duration, and relationship of solicited local and systemic AEs(28 days after the booster dose vaccination)