Clinical trial NCT05254236: Immunogenicity and Safety Study of the 3rd Booster Dose Using the High or Medium Dose of Inactivated Vaccine in Healthy Adults in in Hong Kong
Official title: 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
Study type: INTERVENTIONAL
Overall status: WITHDRAWN
Phase: PHASE2
Conditions: COVID-19
Lead sponsor: Sinovac Biotech Co., Ltd
Sponsor class: INDUSTRY
First posted: 2022-02-24
Enrollment: 0
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: PREVENTION

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.

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.);
* Acute febrile illness with oral temperature \>37.5C on the day of vaccination;
* According to the investigator's judgment, the participant has any other factors that might interfere with the results of the clinical trial or pose additional risk to the participant due to participation in the study.

Primary outcomes:
measure: Immunogenicity index-Geometric mean fold rise (GMFR) of neutralization antibody titre in the high dose
timeFrame: 28 days after the booster dose vaccination
measure: Immunogenicity index-Geometric mean fold rise (GMFR) of neutralization antibody titre in the medium dose
timeFrame: 28 days after the booster dose vaccination
Secondary outcomes:
measure: Immunogenicity index-the seropositivity rate of neutralizing antibody in the high dose
timeFrame: 28 days after the booster dose vaccination
measure: Immunogenicity index-the seropositivity rate of neutralizing antibody in the medium dose
timeFrame: 28 days after the booster dose vaccination
measure: Immunogenicity index-Geometric mean of neutralizing antibody titer (GMT) in the medium dose
timeFrame: 28 days after the booster dose vaccination
measure: Immunogenicity index-Geometric mean of neutralizing antibody titer (GMT)in the medium dose
timeFrame: 28 days after the booster dose vaccination
measure: Immunogenicity index-The seropositivity rate of neutralizing antibody in the high dose
timeFrame: 3 months after the booster dose vaccination
measure: Immunogenicity index-The seropositivity rate of neutralizing antibody in the medium dose
timeFrame: 3 months after the booster dose vaccination
measure: Immunogenicity index-The seropositivity rate in the high dose
timeFrame: 6 months after the booster dose vaccination
measure: Immunogenicity index-The seropositivity rate in the medium dose
timeFrame: 6 months after the booster dose vaccination
measure: Immunogenicity index-GMT of neutralizing antibody in the high dose
timeFrame: 3 months after the booster dose vaccination
measure: Immunogenicity index-the GMT of neutralizing antibody in the high dose
timeFrame: 6 months after the booster dose vaccination
measure: Immunogenicity index-GMT of neutralizing antibody in the medium dose
timeFrame: 3 months after the booster dose vaccination
measure: Immunogenicity index-the GMT of neutralizing antibody in the medium dose
timeFrame: 6 months after the booster dose vaccination
measure: Safety index-Occurrence, intensity, duration, and relationship of solicited local and systemic AEs
timeFrame: 28 days after the booster dose vaccination
measure: Safety index-Occurrence and relationship of SAEs
timeFrame: Within 12 months post booster vaccination
measure: Safety index-Occurrence and relationship of AESI
timeFrame: Within 12 months post booster vaccination
Other outcomes:
Locations:
city: Hong Kong
country: China
facility: Gleneagles Hospital HongKong
Study officials:
affiliation: Gleneagles Hospital HongKong
name: Ivan Fan Ngai HUNG, Doctor
role: PRINCIPAL_INVESTIGATOR
References: