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Covid19Phase 2NCT05035238

Evaluation of the Efficacy, Safety and Immunogenicity of Inactivated COVID 19 Vaccine(TURKOVAC) in Healthy Population of 18 and 64 Years of Age (Both Inclusive):a Randomized, Double-blind, Phase IIb Clinical Trial

A Phase 2 study testing Triple dose vaccination by inactivated Covid19 vaccine in people with Covid19, run by Health Institutes of Turkey at 1 site in Turkey (Türkiye).

Withdrawn

Withdrawn. The study stopped before anyone enrolled.

Official record
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Trial summary

The objective of this study is to evaluate the efficacy, immunogenicity and safety of two different strengths (3 µg/0.5 mL and 4,5 µg/0.5 mL) of inactivated COVID 19 Vaccine- TURKOVAC in healthy subjects following 3rd vaccination to demonstrate clinical evidence in prophylaxis of COVID 19. Read more about this study

Who is it for?
Ages 18 to 64 yearsHealthy volunteers can take part
Conditions the study is for
Covid19
What is being tested?
Triple dose vaccination by inactivated Covid19 vaccine
Could I receive a placebo?
No, everyone receives an active treatment
How many people
0 participants
Where
1 siteTurkey (Türkiye)
Study dates
1 Oct 2021to 1 Oct 2021
Phase
Phase 2
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 64 years
  • All sexes
  • Healthy volunteers accepted
  • Adult

Who may be able to join

  • Caucasian race, 18 to 64 years of age male or female (both inclusive),
  • accepting not to participate in another COVID-19 vaccine study until the end of the study,
  • voluntarily gives written informed consent prior to any study-related procedures.
  • has a Body Mass Index (BMI) of 18.5-32.0 kg/m2-both inclusive,
  • has a normal/acceptable ECG result
  • for female volunteers of childbearing potential, a negative serum pregnancy test within seven days before vaccination:
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  • Females of childbearing potential are defined as fertile following menarche and until becoming postmenopausal or permanently sterile. (Postmenopausal is defined as absence of vaginal bleeding or spotting for at least one year. Permanently sterile is defined as having had a hysterectomy, bilateral salpingectomy, or bilateral oophorectomy.)
  • for female volunteers of childbearing potential, volunteers who do not plan to get a child in the next one year; a willingness to use highly effective* contraceptive measures adequate to prevent a new pregnancy for the duration of the study, including for at least 12 months after receiving the first dose of study vaccination. For women with reproductive potential who use a hormonal method of contraception, concurrent use of a second (barrier) method is recommended.
  • Highly effective methods of birth control are defined as those that result in a low failure rate (i.e. less than 1% per year) when used consistently and correctly (e.g. implants, injectables, oral contraceptives, some intrauterine devices, bilateral tubal occlusion, true sexual abstinence in line with the preferred and usual lifestyle of the volunteer, or vasectomized partner).
  • for sexually active males, a willingness to use contraceptive measures, e.g. a condom, for the duration of the study, including for at least three months after receiving the last dose of study vaccination. In addition, males must agree not to donate sperm over the same study period and for at least three months after receiving the last dose of study vaccination.
  • anti-SARS CoV 2 total antibody (including COVID-19 IgG and/or IgM) negative in serum.
  • physical examination, if indicated only (general state and abnormal findings per system: endocrine/metabolic, allergies, drug sensitivities, head, neck, eyes, ears, nose, throat, cardiovascular, respiratory, gastrointestinal, hepatic/biliary, urogenital, musculoskeletal, lymph nodes, skin, and neurological/psychiatric) should be normal/acceptable.

Who cannot join

  • clinically significant infection or other acute illness not due to SARS-CoV-2, including fever ≥ 37.4°C within 24 hours prior to the planned study vaccination.
  • had close contact to persons with confirmed SARS-CoV-2 infection within 14 days prior to screening Visit 1.
  • has participated in a clinical study involving an investigational SARS-CoV-2 vaccine.
  • has a history of SARS-CoV-1 or MERS infection (self-reported).
  • positive test results for human immunodeficiency virus (HIV), hepatitis B surface antigen (HBsAg) or hepatitis C virus (HCV).
  • has received any vaccine within 30 days prior Visit 1 other than the study intervention, with the exception of the seasonal influenza vaccination.
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  • has abnormal findings in any required study investigations (including medical history, vital signs, physical examination, and clinical laboratory) considered clinically relevant by the Investigator.
  • with either medical history of or present acute or progressive, unstable or uncontrolled clinical conditions that pose a risk for participation or completion of the study, based on Investigator's clinical judgement.
  • with underlying diseases with a high risk of developing severe COVID-19 symptoms if infected.
  • has a history of malignancy in the past five years other than squamous cell or basal cell skin cancer. If there has been surgical excision or treatment more than five years ago that is considered to have achieved a cure, the subject may be enrolled. A history of hematologic malignancy is a permanent exclusion. Subjects with a history of skin cancer must not be vaccinated at the previous tumor site.
  • has a known or suspected defect of the immune system, such as subjects with congenital or acquired immune deficiency.
  • received immuno-suppressive therapy within four weeks prior to Visit 1 or receipt of immunosuppressive therapy is expected during the study.
  • has a history of any vaccine related contraindicating event.
  • presents with clinical conditions representing a contraindication to intramuscular vaccination and blood draws.
  • has donated blood, blood fractions or plasma within four weeks prior to Visit 1 or received blood-derived products (e.g., plasma) within 12 weeks prior to Visit 1 in this study or plans to donate blood or use blood products during the study.
  • with clinically significant bleeding disorder (e.g., factor deficiency, coagulopathy or platelet disorder) or prior history of significant bleeding or bruising following IM injections or venipuncture.
  • has a rash, dermatological condition or tattoos that would, in the opinion of the Investigator, interfere with injection site reaction rating.
  • has a known or suspected problem with alcohol, caffeine or drug abuse as determined by the Investigator.
  • has any condition that, in the opinion of the Investigator, may compromise the subject's well-being, might interfere with evaluation of study endpoints, or would limit the subject's ability to complete the study.
  • has participated in another clinical study involving an investigational medicinal product (IMP) or device within 4 weeks prior to Visit 1 or is scheduled to participate in another clinical study involving an IMP, or device during this study.
  • blood pressure, after resting for five min, higher than 140/90 or lower than 100/60 mm Hg.
  • pulse rate outside the range of 50 - 100 beats/min OR respiratory rate outside the range of 15 - 18 breathings /min, after resting for five min.
  • laboratory values (blood/serum examination: sodium, potassium, calcium, total protein, albumin, glucose, creatinine, BUN, total bilirubin, AST, ALT, GGT, ALP, hemoglobin, hematocrit, erythrocytes, leukocytes, platelet count; HBsAg, HIV-Ab, HCV-Ab, urinalysis if requested) outside normal range with clinical relevance at entry.
  • intake or administration of OTC medication (including herbal remedies) which may have an effect on the study according to the investigator within 2 weeks prior to the start of the study.
  • legal incapacity and/or other circumstances rendering the subject unable to understand the nature, scope and possible consequences of the study.
  • is a member of the team conducting the study or in a dependent relationship with one of the study team members.

Trial locations and contacts

1 site in 1 country.

Turkey (Türkiye)1 site

  • Erciyes University Hakan Çetinsaya Iyi Klinik Uygulama ve Arastirma Merkezi, IKUM (Center for GCP)

    Kayseri, 38038

Other trials in Turkey (Türkiye)

About this study

Official title: Evaluation of the Efficacy, Safety and Immunogenicity of Inactivated COVID 19 Vaccine (TURKOVAC Inactive) in Healthy Population of 18 and 64 Years of Age (Both Inclusive): a Randomized, Double-blind, Phase IIb Clinical Trial

The objective of this study is to evaluate the efficacy, immunogenicity and safety of two different strengths (3 µg/0.5 mL and 4,5 µg/0.5 mL) of inactivated COVID 19 Vaccine- TURKOVAC in healthy subjects following 3rd vaccination to demonstrate clinical evidence in prophylaxis of COVID 19.

Read the detailed description

This is a double-blind, triple dose, parallel, randomized design study comparing two different dose levels and immunization regimen of a novel COVID-19 vaccine candidate - TURKOVAC - against SARS-CoV-2 infection, to assess the efficacy and safety of these vaccine strengths after 3rd dose vaccination. This study will also provide more data to assess the efficacy of the 3rd dose vaccination (booster dose) for COVID-19 prophylaxis including comparison to a cohort of standard convalescent serum samples obtained from World Health Organization (WHO).

This study will be completed in 12 months.

Conditions
Covid19
Being tested
Triple dose vaccination by inactivated Covid19 vaccine
Keywords
Inactivated vaccine, Phase IIb, Severe acute respiratory syndrome
Medical subject headings
COVID-19, Severe Acute Respiratory Syndrome

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Triple dose vaccination by inactivated Covid19 vaccineBiological

    triple dose intramuscular vaccine on Day 0, Day 28, and Day 120.

Study groups in NCT05035238
Study groupRoleWhat they receive
Arm 1Active comparator3 μg / 0.5 mL
Receives: Biological: Triple dose vaccination by inactivated Covid19 vaccine
Arm 2Active comparator4,5 μg / 0.5 mL
Receives: Biological: Triple dose vaccination by inactivated Covid19 vaccine

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Efficacy Outcome

    comparison of the seroconversion rate-at least 4-fold rise of antibody concentration/titre from pre- to post-vaccination

    Measured: on day 14 and 28 after 3rd vaccination

  2. Efficacy Outcome

    comparison of antibody concentrations (GMC) or titres (GMT) from pre- to post-vaccination; Specific ELISA antibody titres against SARS-COV-2 spike glycoprotein

    Measured: on day 14 and 28 after 3rd vaccination

  3. Efficacy Outcome

    comparison of neutralizing antibodies and cytokine (TNF-alpha, IFN-γ, IL-2, IL-4, IL-5 and IL-6) from pre- to post-vaccination

    Measured: on day 14 and 28 after 3rd vaccination

  4. Efficacy outcome

    • comparison of antibody responses levels of minimum of 40 participants to convalescent serum plasma obtained from WHO from pre- to post-vaccination

    Measured: on day 14 and 28 after 3rd vaccination

Secondary outcomes (1)

  1. Safety outcome

    Adverse events and safety laboratory results

    Measured: 12 months

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted5 Sep 2021
  2. Study start1 Oct 2021 (estimated)
  3. Primary completion1 Oct 2021 (estimated)
  4. Study completion1 Oct 2021 (estimated)

Why it stopped: the clinical trial did not initiated

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 2
Primary purpose
Prevention
Allocation
Randomised
Intervention model
Parallel groups
Model description
Each subject will receive triple intramuscular dose of TURKOVAC 3 µg/0.5 mL or 4,5 µg/0.5 mL Vaccine on Day 0, Day 28, and Day 120. 200 healthy subjects in both genders will be dosed in double blinded groups with 1:1 randomization ratio.
Masking
Triple blind
Who is masked
Participant, Investigator, Outcomes assessor
Enrolment
0 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05035238
Sponsor's protocol ID
TSB-VAC-COV-TUR-KF2B.03
Status last verified
Sep 2021
First submitted
1 Sep 2021
Last updated
28 May 2025
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Questions about this trial

What is this clinical trial studying?

A Phase 2 study testing Triple dose vaccination by inactivated Covid19 vaccine in people with Covid19, run by Health Institutes of Turkey at 1 site in Turkey (Türkiye).

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 12 inclusion and 26 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: withdrawn, as of the sponsor's last update on 28 May 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Turkey (Türkiye). Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

The study was withdrawn before enrolling participants, so there are no results.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Efficacy Outcome (time frame: on day 14 and 28 after 3rd vaccination). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT05035238.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 28 May 2025.

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