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COVID-19Phase 2NCT05904054

Immunogenicity and Safety Study of SARS-CoV-2 DNA Vaccine (ICCOV)

A Phase 2 study testing SARS-CoV-2 DNA Vaccine (ICCOV) in people with COVID-19, run by Immuno Cure 3 Limited at 1 site in Hong Kong.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

This is an open-labeled, no placebo, Phase IIa clinical trial. The purpose of this study is to evaluate the immunogenicity and safety of one booster vaccine dose of SARS-CoV-2 DNA Vaccine (ICCOV) in adults aged 18 to 75 years who have received two to four dosese of COVID-19 vaccine. Read more about this study

Who is it for?
Ages 18 to 75 yearsHealthy volunteers can take part
Conditions the study is for
COVID-19
What is being tested?
SARS-CoV-2 DNA Vaccine (ICCOV)
Could I receive a placebo?
No, everyone receives an active treatment
How many people
31 participants
Where
1 siteHong Kong
Study dates
15 Jun 2023to 31 May 2024
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 75 years
  • All sexes
  • Healthy volunteers accepted
  • Adult, Older adult

Who may be able to join

  • Able and willing to comply with all study requirements.
  • Give informed consent and sign informed consent form (ICF). For subjects who are unable to read or write, the consent must be witnessed by a literate third party not involved in the study.
  • BMI in between 18.5 and 30.0 kg/m2 (including upper and lower limits).
  • For each group, meet the following criteria regarding age, COVID-19 vaccination history (as confirmed by COVID-19 vaccination records), and SARS-CoV-2 infection history (as confirmed by the investigator according to WHO definitions, Appendix III):
  • Group 1: Adult-CoronaVac® group
  • Aged 18-59 AND received 2 to 4 homologous doses of CoronaVac® at least 3 months prior to enrollment AND without SARS-CoV-2 infection history.
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  • Group 2: Adult-Comirnaty® group
  • Aged 18-59 AND received 2 to 4 heterologous doses of CoronaVac® and Comirnaty® at least 3 months prior to enrollment AND without SARS-CoV-2 infection history; OR
  • Group 3: Adult-mixed group
  • Aged 18-59 AND received 2 to 4 heterologous doses of CoronaVac® and Comirnaty® at least 3 months prior to enrollment AND without SARS-CoV-2 infection history; OR
  • Aged 18-59 AND received 2 to 4 heterologous doses of CoronaVac® and Comirnaty® at least 3 months prior to enrollment AND recovered from SARS-CoV-2 infection at least 3 months prior to enrollment; OR
  • Aged 18-59 AND received 2 to 4 homologous doses of CoronaVac® or Comirnaty® at least 3 months prior to enrollment AND recovered from SARS-CoV-2 infection at least 3 months prior to enrollment.
  • Group 4: Elderly-mixed group
  • Aged 60-75 AND received 2 to 4 heterologous doses of CoronaVac® and Comirnaty® at least 3 months prior to enrollment AND without SARS-CoV-2 infection history; OR
  • Aged 60-75 AND received 2 to 4 heterologous doses of CoronaVac® and Comirnaty® at least 3 months prior to enrollment AND recovered from SARS-CoV-2 infection at least 3 months prior to enrollment; OR
  • Aged 60-75 AND received 2 to 4 homologous doses of CoronaVac® or Comirnaty® at least 3 months prior to enrollment AND without SARS-CoV-2 infection history; OR
  • Aged 60-75 AND received 2 to 4 homologous doses of CoronaVac® or Comirnaty® at least 3 months prior to enrollment AND recovered from SARS-CoV-2 infection at least 3 months prior to enrollment.
  • Healthy subjects, or subjects with stable medical condition who have a pre-existing medical condition that does not meet any exclusion criteria. A stable medical condition is defined as disease not requiring significant change in therapy or hospitalization for worsening disease during the 3 months prior to enrollment.
  • Female subjects of childbearing potential with have negative pregnancy test shall be willing to practice continuous effective contraception and not to breastfeed until 12 months after ICCOV administration.
  • Nonchildbearing potential is defined as surgically sterile (history of bilateral tubal ligation, bilateral oophorectomy, hysterectomy) or postmenopausal. A follicle-stimulating hormone (FSH) level and the amenorrhea duration (e.g., amenorrhea for ≥ 12 consecutive months prior to screening without an alternative medical cause) may be measured at the discretion of the investigator to confirm postmenopausal status.
  • The effective contraceptive methods include sexual abstinence or adequate contraceptive measures such as intrauterine or implanted contraceptive device, oral contraceptives, injected or implanted contraceptives, sustained-release topical contraceptives, condoms (male), diaphragm, and cervical cap, etc.
  • Male subjects who are involved in heterosexual sexual activity must agree to practice adequate contraception (as described above) and refrain from donating sperm until 12 months after ICCOV administration.
  • Agreement to avoid blood donation during the study.

Who cannot join

  • Laboratory confirmed SARS-CoV-2 infection, defined by RT-PCR test.
  • Fever (oral temperature ≥ 37.5°C/axillary temperature ≥ 37.3°C) on the day of vaccination or within recent 72 hours.
  • Medical history of severe acute respiratory syndrome (SARS), middle east respiratory syndrome (MERS) within 12 months, and COVID-19 within 3 months prior to enrollment.
  • Abnormal laboratory tests of clinical significance involving hematology, serum biochemistry, coagulation function, or urinalysis as determined by the investigator.
  • Females who are pregnant or breastfeeding or those who plan to give birth in coming 12 months (including in female subjects or the female partners of male subjects).
  • Participated in other clinical trials and received any other investigational products within 1 month (or 5 half-lives of the drug, whichever is longer) prior to enrollment or plan to receive any other investigational products during the study.
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  • History of severe allergies to any vaccine or drug, such as urticaria, dyspnea, edema, abdominal pain and other symptoms after administration, especially hypersensitivity to the components of ICCOV.
  • Have malignant tumor (except for skin basal cell carcinoma or carcinoma uterine cervix in situ) and immune disease (e.g., human immunodeficiency virus [HIV] infection, systemic lupus erythematosus, rheumatoid arthritis, asplenia or splenectomy, severe combined immunodeficiency disorder [SCID], and other immune disease that may influence immune response at the investigator's discretion).
  • Have other severe and/or uncontrolled conditions, including but not limited to, acute infectious disease, cardiovascular disease, respiratory disease, gastrointestinal disease, liver disease, renal disease, hematology disease, endocrine disorder, psychiatric condition and neurological illness (e.g., Guillain-Barre Syndrome, uncontrolled epilepsy, etc.). Mild/moderate well-controlled comorbidities are allowed to participate as deemed appropriate by the investigator.
  • Received any investigational or licensed COVID-19 vaccine other than described in inclusion criteria, or any investigational or approved vaccine against a coronavirus (including but not limited to SARS-CoV-1 and MERS-CoV) at any time prior to enrollment.
  • Received any investigational or approved vaccines within 3 months prior to enrollment or plan to receive any other vaccines during the study.
  • Received any blood products or immunoglobulin products within 3 months prior to enrollment or plan to receive that during the study.
  • Received interferon, systemic corticosteroids, or other immunosuppressants/ immunomodulators (except for local application) for 14 or more consecutive days within 6 months prior to enrollment.
  • Medical history or clinical manifestations of any physical or mental illness that may affect the subject's completion of this study.
  • Needle phobia.
  • Have contraindications for intramuscular administration, such as confirmed thrombocytopenia, any coagulation dysfunction, or being receiving anticoagulation therapy.
  • Have contraindications for electroporation, such as implanted with pacemaker, implanted with Automatic Implantable Cardioverter Defibrillator (AICD), or abnormal electrocardiogram at screening as determined by the investigator.
  • Any other conditions considered by the investigator as not suitable to participate in this study.

Trial locations and contacts

1 site in 1 country.

Hong Kong1 site

  • Gleneagles Hospital Hong Kong

    Wong Chuk Hang

Other trials in Hong Kong

About this study

Official title: An Open-label and Single-center Phase IIa Trial to Evaluate the Immunogenicity and Safety of SARS-CoV-2 DNA Vaccine (ICCOV) in Healthy Subjects Aged 18-75 Years

This is an open-labeled, no placebo, Phase IIa clinical trial. The purpose of this study is to evaluate the immunogenicity and safety of one booster vaccine dose of SARS-CoV-2 DNA Vaccine (ICCOV) in adults aged 18 to 75 years who have received two to four dosese of COVID-19 vaccine.

Read the detailed description

This is an open-labeled, no placebo, Phase IIa clinical trial to evaluate the immunogenicity and safety of one booster vaccine dose of SARS-CoV-2 DNA Vaccine (ICCOV) in adults aged 18 to 75 years who have received two to four dosese of COVID-19 vaccine. The primary purpose of this study is to evaluate cross-reactive T cell responses against SARS-CoV-2 prototype and epidemic variants induced by one booster dose of ICCOV. The secondary purposes are 1) to evaluate other variables of cross-reactive T cell responses against SARS-CoV-2 prototype and epidemic variants induced by one booster dose of ICCOV; 2) to evaluate humoral immunity responses against SARS-CoV-2 prototype and epidemic variants induced by one boosterdose of ICCOV; and 3) to evaluate the safety and reactogenicity of ICCOV.

Conditions
COVID-19
Being tested
SARS-CoV-2 DNA Vaccine (ICCOV)
Keywords
ICCOV, COVID-19, DNA Vaccine
Medical subject headings
COVID-19

What participants receive

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

  • SARS-CoV-2 DNA Vaccine (ICCOV)Biological

    Also called ICCOV

    The SARS-CoV-2 DNA Vaccine (ICCOV) was developed by Immuno Cure Holding (HK) Limited.The product is a pre-filled syringe or a vial with an extractable volume of 0.5 mL. The unit dose strength is 1 mg/0.5 mL and the dose volume is 1.0 mL/dose.

Study groups in NCT05904054
Study groupRoleWhat they receive
Adult-CoronaVac® groupExperimentalAged 18-59 AND received 2 to 4 homologous doses of CoronaVac® at least 3 months prior to enrollment AND without SARS-CoV-2 infection history.
Receives: Biological: SARS-CoV-2 DNA Vaccine (ICCOV)
Adult-Comirnaty® groupExperimentalAged 18-59 AND received 2 to 4 homologous doses of Comirnaty® at least 3 months prior to enrollment AND without SARS-CoV-2 infection history.
Receives: Biological: SARS-CoV-2 DNA Vaccine (ICCOV)
Adult-mixed groupExperimentalAged 18-59 AND received 2 to 4 heterologous doses of CoronaVac® and Comirnaty® at least 3 months prior to enrollment AND without SARS-CoV-2 infection history; OR Aged 18-59 AND received 2 to 4 heterologous doses of CoronaVac® and Comirnaty® at least 3 months prior to enrollment AND recovered from SARS-CoV-2 infection at least 3 months prior to enrollment; OR Aged 18-59 AND received 2 to 4 homologous doses of CoronaVac® or Comirnaty® at least 3 months prior to enrollment AND recovered from SARS-CoV-2 infection at least 3 months prior to enrollment.
Receives: Biological: SARS-CoV-2 DNA Vaccine (ICCOV)
Elderly-mixed groupExperimentalAged 60-75 AND received 2 to 4 heterologous doses of CoronaVac® and Comirnaty® at least 3 months prior to enrollment AND without SARS-CoV-2 infection history; OR Aged 60-75 AND received 2 to 4 heterologous doses of CoronaVac® and Comirnaty® at least 3 months prior to enrollment AND recovered from SARS-CoV-2 infection at least 3 months prior to enrollment; OR Aged 60-75 AND received 2 to 4 homologous doses of CoronaVac® or Comirnaty® at least 3 months prior to enrollment AND without SARS-CoV-2 infection history; OR Aged 60-75 AND received 2 to 4 homologous doses of CoronaVac® or Comirnaty® at least 3 months prior to enrollment AND recovered from SARS-CoV-2 infection at least 3 months prior to enrollment.
Receives: Biological: SARS-CoV-2 DNA Vaccine (ICCOV)

What is being measured

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

  1. Frequencies of cross-reactive receptor binding domain (RBD)-specific IFN-γ producing T cells at Day 14

    Frequencies of cross-reactive receptor binding domain (RBD)-specific RBD-specific IFN-γ producing T cells at Day 14 after ICCOV administration compared to baseline (Day 0), as measured by numbers of IFN-γ+ spot-forming unit /1 million PBMC by ELISpot assay.

    Measured: Day 14

  2. Frequencies of cross-reactive receptor binding domain (RBD)-specific IFN-γ producing T cells at Day 28

    Frequencies of cross-reactive receptor binding domain (RBD)-specific RBD-specific IFN-γ producing T cells at Day 28 after ICCOV administration compared to baseline (Day 0), as measured by numbers of IFN-γ+ spot-forming unit /1 million PBMC by ELISpot assay.

    Measured: Day 28

  3. Frequencies of cross-reactive receptor binding domain (RBD)-specific CD4+ T cells at Day 14

    Frequencies of cross-reactive RBD-specific CD4+ T cell responses at Day 14 after ICCOV administration compared to baseline (Day 0), as analyzed by flow cytometry-based intracellular cytokine staining assays.

    Measured: Day 14

  4. Frequencies of cross-reactive receptor binding domain (RBD)-specific CD4+ T cells at Day 28

    Frequencies of cross-reactive RBD-specific CD4+ T cell responses at Day 28 after ICCOV administration compared to baseline (Day 0), as analyzed by flow cytometry-based intracellular cytokine staining assays.

    Measured: Day 28

  5. Frequencies of cross-reactive receptor binding domain (RBD)-specific CD8+ T cells at Day 14

    Frequencies of cross-reactive RBD-specific CD8+ T cell responses at Day 14 after ICCOV administration compared to baseline (Day 0), as analyzed by flow cytometry-based intracellular cytokine staining assays.

    Measured: Day 14

  6. Frequencies of cross-reactive receptor binding domain (RBD)-specific CD8+ T cells at Day 28

    Frequencies of cross-reactive RBD-specific CD8+ T cell responses at Day 28 after ICCOV administration compared to baseline (Day 0), as analyzed by flow cytometry-based intracellular cytokine staining assays.

    Measured: Day 28

Secondary outcomes (3)

  1. Frequencies of cross-reactive receptor binding domain (RBD)-specific IFN-γ producing T cells at Day 60

    Frequencies of cross-reactive receptor binding domain (RBD)-specific RBD-specific IFN-γ producing T cells at Day 60 after ICCOV administration, as measured by numbers of IFN-γ+ spot-forming unit /1 million PBMC by ELISpot assay.

    Measured: Day 60

  2. Frequencies of cross-reactive receptor binding domain (RBD)-specific CD8+ T cells at Day 60

    Frequencies of cross-reactive RBD-specific CD8+ T cell responses at Day 60 after ICCOV administration, as analyzed by flow cytometry-based intracellular cytokine staining assays.

    Measured: Day 60

  3. Frequencies of cross-reactive receptor binding domain (RBD)-specific CD4+ T cells at Day 60

    Frequencies of cross-reactive RBD-specific CD4+ T cell responses at Day 60 after ICCOV administration, as analyzed by flow cytometry-based intracellular cytokine staining assays.

    Measured: Day 60

Timeline

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

  1. First posted15 Jun 2023
  2. Study start15 Jun 2023
  3. Primary completion31 Dec 2023
  4. Study completion31 May 2024

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
Non-randomised
Intervention model
Parallel groups
Masking
None (open label)
Enrolment
31 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05904054
Sponsor's protocol ID
ICCOV_HK202301
Status last verified
May 2024
First submitted
2 Jun 2023
Last updated
30 Apr 2025
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
Undecided

Publications

  • Wong YC, Hang Ho DH, Zhou R, Zhang R, Woo KF, Cheng WY, Wang T, Du Y, Polly Pang KP, Tai WK, Jin X, Chen Z, Ngai Hung IF. An open-label study on the safety and immunogenicity of a PD-1-enhanced DNA vaccine used as a T cell booster for COVID-19. EBioMedicine. 2025 May;115:105699. doi: 10.1016/j.ebiom.2025.105699. Epub 2025 Apr 16.

    PubMed 40245494

Questions about this trial

What is this clinical trial studying?

A Phase 2 study testing SARS-CoV-2 DNA Vaccine (ICCOV) in people with COVID-19, run by Immuno Cure 3 Limited at 1 site in Hong Kong.

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 23 inclusion and 18 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: finished, as of the sponsor's last update on 30 Apr 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 Hong Kong. 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 is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

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?

Frequencies of cross-reactive receptor binding domain (RBD)-specific IFN-γ producing T cells at Day 14 (time frame: Day 14). The study lists 6 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 NCT05904054, which also lists 1 linked publication.

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 30 Apr 2025.

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