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Immunogenicity and Safety Study of the 3rd Booster Dose Using the High or Medium Dose of Inactivated (CoronaVac®) Vaccine in Healthy Adults in Turkey

A Phase IIb Randomized Double-Blinded Positive Controlled Trial to Evaluate the Immunogenicity and Safety Study of the 3rd Booster Dose Using the High or Medium Dose of Inactivated (CoronaVac®) Vaccine in Healthy Adults Who Have Completed Two Doses of CoronaVac® or the mRNA Vaccine (Comirnaty) in Turkey

Status
Suspended
Phases
Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT05150496
Enrollment
640
Registered
2021-12-09
Start date
2022-12-15
Completion date
2023-01-15
Last updated
2022-08-11

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

COVID-19

Brief summary

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

Detailed description

This is a randomized, double-blinded, and positive-controlled phaseⅡb clinical trial of 640 participants aged 18 years and above, who have completed 2 doses of inactivated COVID-19 vaccine (CoronaVac®) or mRNA COVID-19 vaccine (Comirnaty) as the primary vaccination. Participants will be enrolled and randomly assigned into two arms at a ratio of 1:1 to receive a booster dose of medium-dose (600SU) or high-dose (1200SU) COVID-19 Vaccine. For those who were vaccinated with CoronaVac®, the booster dose will be given 3-8 months after their second dose. For those who were vaccinated with Comirnaty, the booster dose will be given 6-8 months after their second dose. Each participant will be collected 5.0 ml blood sample before vaccination and 14 days,3 months and 6 months after booster immunization.Immunogenicity assessments will be determined by neutralizing antibodies in all participants.In addition,all participants will be monitored for immediate reactions (within 30 minutes) after the booster dose vaccination, adverse events of special interest (AESIs) and serious adverse events (SAEs) for 12 months after booster dose inoculation. In addition, all participants in will be monitored for local and systemic solicited adverse events (AEs) within 7 days and the unsolicited AEs within 28 days.

Interventions

Medium-dose COVID-19 Vaccine(Vero Cell),Inactivated: 600SU inactivated SARS-CoV-2 virus in 0.5 mL of aluminium hydroxide solution per injection

BIOLOGICALHigh-dose COVID-19 Vaccine(Vero Cell),Inactivated

High-dose COVID-19 Vaccine(Vero Cell),Inactivated:1200SU inactivated SARS-CoV-2 virus in 0.5 mL of aluminium hydroxide solution per injection

Sponsors

Sinovac Research and Development Co., Ltd.
Lead SponsorINDUSTRY

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
DOUBLE (Subject, Investigator)

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes

Inclusion criteria

* Healthy adults aged 18 years and above, who have received 2 prior doses of inactivated COVID-19 vaccine (CoronaVac®) or mRNA COVID-19 vaccine (Comirnaty), with the second dose given 3-8 months (for CoronaVac® recipients) and 6-8 months (for Comirnaty recipients) prior to the day of booster vaccination in the present study; * Antigen rapid testing negative at the day of enrollment on site or with a PCR negative result within 72 hours before enrollment; * The participants are able to understand and sign the informed consent voluntarily; * Female participants who have a negative pregnancy test on the day of vaccination, and not currently breastfeeding; * The participants are planning to be living in Turkey for the following 1 year after attending this study; * 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 currently with the 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 3 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 14 days prior to vaccination in this study; * Receipt of inactivated or subunit vaccines in the past 7 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 axillary temperature \>37.5°C on the day of vaccination; enrollment could be considered if the fever is absent for 72 hours prior to 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.

Design outcomes

Primary

MeasureTime frameDescription
Immunogenicity index-GMT of neutralizing antibodies14 days (14-28 days) after the booster dose vaccinationGMT of neutralizing antibodies on 14 days (14-28 days) after the booster dose vaccination

Secondary

MeasureTime frameDescription
Immunogenicity index-GMT of neutralizing antibodyAt 3 (±2 weeks) and 6 (±2 weeks) months after the booster dose vaccinationGMT of neutralizing antibody at 3 (±2 weeks) and 6 (±2 weeks) months after the booster dose vaccination
Safety index-Occurrence, intensity, duration, and relationship of unsolicited AEs28 days post booster vaccinationOccurrence, intensity, duration, and relationship of unsolicited AEs for 28 days post booster vaccination
Safety index-Occurrence and relationship of SAEsFrom the booster dose to 12 months post booster vaccinationOccurrence and relationship of SAEs (from the booster dose to 12 months post booster vaccination)
Safety index-Occurrence and relationship of AESIFrom the booster dose to 12 months post booster vaccinationOccurrence and relationship of AESI (from the booster dose to 12 months post booster vaccination)
Immunogenicity index-Seropositivity rate of neutralizing antibodies14 days (14-28 days) after the booster dose vaccinationSeropositivity rate of neutralizing antibodies on 14 days (14-28 days) after the booster dose vaccination
Immunogenicity index-GMI of neutralizing antibodies14 days (14-28 days) after the booster dose vaccinationGMI of neutralizing antibodies on 14 days (14-28 days) after the booster dose vaccination
Immunogenicity index-The seropositivity rate of neutralizing antibodyAt 3 (±2 weeks) and 6 (±2 weeks) months after the booster dose vaccinationSeropositivity rate of neutralizing antibody at 3 (±2 weeks) and 6 (±2 weeks) months after the booster dose vaccination
Safety index-Occurrence, intensity, duration, and relationship of solicited local and systemic AEs7 days following the booster dose vaccinationOccurrence, intensity, duration, and relationship of solicited local and systemic AEs for 7 days following the booster dose vaccination

Other

MeasureTime frameDescription
Immunogenicity index-GMI of neutralizing antibodiesBefore vaccination, 14 days (14-28 days) , 3-month (±2 weeks), and 6-month (±2 weeks) after the booster dose vaccinationGMI of neutralizing antibodies before vaccination, 14 days (14-28 days) , 3-month (±2 weeks), and 6-month (±2 weeks) after the booster dose vaccination
Immunogenicity index-GMT of neutralizing antibodiesBefore vaccination, 14 days (14-28 days) , 3-month (±2 weeks), and 6-month (±2 weeks) after the booster dose vaccinationGMT of neutralizing antibodies before vaccination, 14 days (14-28 days) , 3-month (±2 weeks), and 6-month (±2 weeks) after the booster dose vaccination
Immunogenicity index-The seropositivity rate of neutralizing antibodiesBefore vaccination, 14 days (14-28 days) , 3-month (±2 weeks), and 6-month (±2 weeks) after the booster dose vaccinationThe seropositivity rate of neutralizing antibodies before vaccination, 14 days (14-28 days) , 3-month (±2 weeks), and 6-month (±2 weeks) after the booster dose vaccination

Countries

Turkey (Türkiye)

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026