CompletedNCT05411471Updated Sep 22, 2023

Immunogenicity and Safety Study of Booster Vaccine With the COVID-19 Vaccine (Vero Cell), Inactivated, Omicron Strain

A Phase 2 interventional study of COVID-19 Vaccine (Vero Cell), Inactivated, Omicron Strain in COVID-19, sponsored by Sinovac Biotech (Hong Kong) Limited. Completed at 1 site in China. Open to participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2023-09-22.

Sponsored by Sinovac Biotech (Hong Kong) Limited · Phase 2, Interventional, and Prevention

Phase: Phase 2
Study type: Interventional
Enrollment: 221
Allocation: Randomized
Ages: 18 Years and older
Sex: All

Study summary

This is a randomized, open-labeled, Phase IIb clinical trial.The purpose of this study is to evaluate the immunogenicity and safety of the booster vaccine of using one or two doses of COVID-19 Vaccine (Vero Cell), Inactivated, Omicron Strain in Adults above 18 Years Old Who Have Completed Two or Three Doses of mRNA Vaccine or CoronaVac®.

Read the detailed description

This is a randomized, open-labeled, Phase IIb clinical trial of 300 participants aged 18 years and above, who have completed two or three doses of mRNA vaccine or CoronaVac® in Hong Kong for at least 90 days after the last dose. After enrollment, the participants will be assigned to 2 groups according to their previous vaccination (mRNA vaccine group and CoronaVac® group) and then each group will be randomly assigned to two study arms at a ratio of 1:1 to receive one or two booster doses of COVID-19 Vaccine (Vero Cell), Inactivated, Omicron Strain.

Conditions studied

COVID-19

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In context

COVID-19

7,640 studies on the registry are indexed under COVID-19; 488 are open to participants now.

This study's enrollment of 221 is above the median of 100 across 4,099 interventional studies indexed under COVID-19.

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Lead sponsor

This is the only study on the registry with Sinovac Biotech (Hong Kong) Limited as lead sponsor.

Counted across the registry records on this site, refreshed daily.

Who can participate

Ages eligible: 18 Years and older
Sexes eligible: All
Accepts healthy volunteers: Yes

Inclusion criteria

Healthy adults aged 18 years and above, who have received two or three prior doses of mRNA COVID-19 vaccine (Comirnaty®, made by BioNTech/Pfizer) or CoronaVac®, with the last dose given at least 90 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 the first dose of the booster vaccine in the present study, and are not currently breastfeeding;
The participants are able to understand and sign the informed consent voluntarily before the first dose of booster vaccine in the present study;
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

Exclusion Criteria:

History of confirmed or having evidence showing a current infection of SARS-CoV-2 prior to randomization or vaccination;
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 first vaccination in this study;
Participation in other studies involving study intervention within 30 days prior to first vaccination in this study;
Receipt of attenuated live vaccines in the past fourteen days prior to each vaccination in this study;
Receipt of inactivated or subunit vaccines in the past seven days prior to each 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 >37.5°C on the day of each 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.

Study design

Phase: Phase 2
Primary purpose: Prevention
Allocation: Randomized
Intervention model: Parallel assignment
Masking: None (open label)
Enrollment: 221 participants (actual)

Study arms

Experimental
Arm 1 (1 dose Omicron Vaccine arm, mRNA vaccine group)
75 participants who have completed two/three doses of mRNA vaccine (prior to this study) will receive one dose COVID-19 Vaccine (Vero Cell), Inactivated, Omicron Strain(1200 SOU).
Biological: COVID-19 Vaccine (Vero Cell), Inactivated, Omicron Strain
Experimental
Arm 2 (2 doses Omicron Vaccine arm, mRNA vaccine group)
75 participants who have completed two/three doses of mRNA vaccine (prior to this study) will receive two doses COVID-19 Vaccine (Vero Cell), Inactivated, Omicron Strain (0,28 days)(1200 SOU).
Biological: COVID-19 Vaccine (Vero Cell), Inactivated, Omicron Strain
Experimental
Arm 3 (1 dose Omicron Vaccine arm, CoronaVac® group)
75 participants who have completed two/three doses of CoronaVac®(prior to this study) will receive one dose COVID-19 Vaccine (Vero Cell), Inactivated, Omicron Strain (1200 SOU).
Biological: COVID-19 Vaccine (Vero Cell), Inactivated, Omicron Strain
Experimental
Arm 4 (2 doses Omicron Vaccine arm, CoronaVac® group)
75 participants who have completed two/three doses of CoronaVac®(prior to this study) will receive two doses COVID-19 Vaccine (Vero Cell), Inactivated, Omicron Strain (0,28 days)(1200 SOU).
Biological: COVID-19 Vaccine (Vero Cell), Inactivated, Omicron Strain

Interventions

BiologicalCOVID-19 Vaccine (Vero Cell), Inactivated, Omicron Strain
The COVID-19 vaccine (Vero cell), Inactivated, Omicron Strain was developed by Sinovac Life Science Ltd.The product is a pre-filled syringe or a vial with an extractable volume of 0.5 mL. The antigen content is 1200 SOU/0.5 mL (6 µg/0.5 mL).
Also known as: COVID-19 Omicron Vaccine

What researchers measure

Primary outcomes

Geometric mean of neutralization antibody titre (GMT)
Geometric mean of neutralization antibody titre (GMT) on Day 14 after the last booster dose against the Omicron variant in different groups
Time frame: Day 14 after the last booster dose
Occurrence, intensity, duration, and relationship of solicited local and systemic AEs
Occurrence, intensity, duration, and relationship of solicited local and systemic AEs for 7 days following each booster dose vaccination and of unsolicited AEs for 28 days post booster vaccination
Time frame: 28 days post booster vaccination

Secondary outcomes

Seroconversion rate of neutralization antibody
Seroconversion rate of neutralization antibody against the omicron variant on Day 14 after the last booster dose in different groups
Time frame: Day 14 after the last booster dose
Seropositivity rate of neutralization antibody
Seropositivity rate of neutralization antibody against the omicron variant on Day 14 after the last booster dose in different groups
Time frame: Day 14 after the last booster dose
Occurrence and relationship of SAEs
Occurrence and relationship of SAEs within 6 months post booster vaccination.
Time frame: within 6 months post booster vaccination

Other outcomes

Seropositive rate of neutralizing antibody
Seropositive rate of neutralizing antibody to SARS-CoV-2 at 90 days and 183 days after one or two doses of booster vaccination in different groups
Time frame: At 90 days and 183 days after one or two doses of booster vaccination
GMT of neutralizing antibody
GMT of neutralizing antibody to SARS-CoV-2 at 90 days and 183 days after one or two doses of booster vaccination in different groups
Time frame: At 90 days and 183 days after one or two doses of booster vaccination

Study locations

1 site

Gleneagles Hospital HongKong
Hong Kong, China

Updates

Tracking since Sep 25, 2026

No changes since tracking began. The registry record was last updated on Sep 22, 2023, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗

Registry details

Key details

Study ID: NCT05411471
Lead sponsor: Sinovac Biotech (Hong Kong) Limited
Responsible party: Sponsor
First posted: Jun 9, 2022
Start date: Jun 8, 2022
Primary completion: Jun 25, 2023
Completion: Jun 25, 2023
Last update: Sep 22, 2023

Study contacts

Ivan HUNG Fan Ngai, Doctor

principal investigator · Gleneagles Hospital HongKong

Oversight

Data monitoring committee: No
FDA-regulated drug: No
FDA-regulated device: No

View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is completed, as verified in Sep 2023. You cannot join it, but the record below documents what was studied.

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