AzTrials
AzTrials

Covid-19Phase 2NCT05054621

Immunogenicity of COVID-19 Vaccine on Heterologous Schedule

A Phase 2 study testing Heterologous prime-boost schedule with AZD1222 and MVC-COV1901 and Homologous prime-boost schedule with two doses of AZD1222 in people with Covid-19 and Vaccine, run by Chang Gung Memorial Hospital at 1 site in Taiwan.

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 a prospective, single blinded randomized homologous/heterologous prime-boost vaccine clinical study, designed to assess the immunogenicity of heterologous prime-boost immunization with AZD1222 and MVC-COV1901 in adults. Read more about this study

Who is it for?
Ages 20 to 70 yearsHealthy volunteers can take part
Conditions the study is for
Covid-19, Vaccine, Immunogenicity
What is being tested?
Heterologous prime-boost schedule with AZD1222 and MVC-COV1901 and Homologous prime-boost schedule with two doses of AZD1222
Could I receive a placebo?
No, everyone receives an active treatment
How many people
100 participants
Where
1 siteTaiwan
Study dates
15 Sep 2021to 31 Aug 2022
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 20 to 70 years
  • All sexes
  • Healthy volunteers accepted
  • Adult, Older adult

Who may be able to join

  • Participant is willing and able to give written informed consent for participation in the trial.
  • Male or Female, aged from 20 to 70 years
  • Has received one dose of the AZD1222 within 28-70 days before randomization. Evidence of this will be gathered from medical history and/or medical records including the COVID-19 vaccine registration yellow card.
  • Female participant must:
  • Be either of non-childbearing potential, i.e. surgically sterilized (defined as having undergone hysterectomy and/or bilateral oophorectomy and/or bilateral salpingectomy; tubal ligation alone is not considered sufficient) or one year post-menopausal;
  • Or, if of childbearing potential, be abstinent or agree to use medically effective contraception on enrolment continuously until 90 days after boost immunization of study intervention.
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  • Acceptable forms include:
  • Implanted hormonal methods of contraception or placement of an intrauterine device or intrauterine system ii. Established use of hormonal methods (injectable, pill, patch or ring) combined with barrier methods of contraception: condom or occlusive cap (diaphragm or cervical/vault caps) with spermicidal foam/gel/film/cream/suppository c. Have a negative pregnancy test.
  • In the Investigator's opinion, is able and willing to comply with all trial requirements.

Who cannot join

  • -
  • The participant may not enter the trial if ANY of the following apply:
  • Previous receipt of two or more COVID-19 vaccine doses
  • History of anaphylaxis, severe allergic disease or reactions likely to be exacerbated by any component of study vaccines (e.g. hypersensitivity to the active substance or any of the listed ingredients of any study vaccine). This includes latex and polyethylene glycol/macrogol (PEG)
  • Pregnancy, lactation or willingness/intention to become pregnant within 3 months post boost vaccine
  • Malignancy requiring receipt of immunosuppressive chemotherapy or radiotherapy for treatment of solid organ cancer/hematological malignancy within the 6 months prior to enrolment.
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  • Bleeding disorder (e.g. factor deficiency, coagulopathy or platelet disorder), or prior history of significant bleeding or bruising following intramuscular injections or venipuncture.
  • Suspected or known current alcohol or drug dependency.
  • Any other significant disease, disorder or finding which may significantly increase the risk to the volunteer because of participation in the study, affect the ability of the volunteer to participate in the study or impair interpretation of the study data.
  • Insufficient level of language to undertake all study requirements in opinion of the Investigators.
  • Known HIV antibody positive.

Trial locations and contacts

1 site in 1 country.

Taiwan1 site

  • ChangGungMH

    Taoyuan, Taiwan, 333

Other trials in Taiwan

About this study

Official title: A Single-blind, Randomized Study to Evaluate the Immunogenicity of Heterologous Prime-boost COVID-19 Vaccine Schedule

This is a prospective, single blinded randomized homologous/heterologous prime-boost vaccine clinical study, designed to assess the immunogenicity of heterologous prime-boost immunization with AZD1222 and MVC-COV1901 in adults.

Participants will be healthy adults at the age of 20-70 years who have had their first dose of COVID-19 vaccine, AZD1222. All eligible participants of 2 prime-boost interval strata (28 to 42, 56 to 70 days) will be 1:1 randomly assigned to receive a single dose of either:

Read more
  • Homologous group: Intramuscular injection the same vaccine as their prime dose AZD1222
  • Heterologous group: Medigen COVID-19 vaccine MVC-COV1901. The treatment phase of this study will be conducted in a single-blind fashion such that the subject will not know the identity of the subjects' study treatment assignment. After receiving the treatment, the participants will remain on study for 168 days following the boost vaccination.

For the study primary objective, immunogenicity will be assessed during the duration of the study, including serologic neutralizing antibody titer against SARS-CoV-2, serological quantification of binding antibody to SARS-CoV-2 antigen, SARS-CoV-2 antigen specific B cell and T cell frequencies and cytokine levels.

And Safety will be assessed during the duration of the study as follows:

  • Solicited adverse events (AEs; local and systemic) will be assessed for 7 days following each vaccination (Day 0 through Day 7 for the boost vaccination).
  • Unsolicited AEs will be recorded for 28 days following the boost vaccination.
  • Serious adverse events (SAEs) will be recorded from signing of the informed consent form through Day 168.
  • Adverse events of special interest (AESIs) will be recorded from the boost vaccination through Day 168.

This study is going to be conducted in a single medical center in Taiwan. An appropriate number of participants will be screened to achieve approximately 44 evaluable participants for each group. Participants in each group will be divided into two subgroups according to the intervals, 28-42 days and 56-70 days, between the prime and booster doses.

Being tested
Heterologous prime-boost schedule with AZD1222 and MVC-COV1901, Homologous prime-boost schedule with two doses of AZD1222
Medical subject headings
COVID-19

What participants receive

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

  • Heterologous prime-boost schedule with AZD1222 and MVC-COV1901Biological

    Participants will be divided into two subgroups according to the intervals, 28-42 days and 56-70 days, between the prime and booster doses.

  • Homologous prime-boost schedule with two doses of AZD1222Biological

    Participants will be divided into two subgroups according to the intervals, 28-42 days and 56-70 days, between the prime and booster doses.

Study groups in NCT05054621
Study groupRoleWhat they receive
Heterologous groupExperimental1st dose AZD1222, 2nd dose MVC-COV1901
Receives: Biological: Heterologous prime-boost schedule with AZD1222 and MVC-COV1901
Homologous group (control)Active comparator1st dose AZD1222, 2nd dose AZD1222
Receives: Biological: Homologous prime-boost schedule with two doses of AZD1222

What is being measured

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

  1. Immunogenicity: Neutralizing antibody against SARS-CoV-2

    To determine if the immune response to heterologous prime-boost immunization with ChAdOx1 nCOV-19 (AZD1222) and MVC-COV1901 is non-inferior to homologous prime-boost immunization with ChAdOx1 nCOV-19, in enrolled adult participants

    Measured: Day 28 after booster dose

Secondary outcomes (4)

  1. Immunogenicity：Anti-SARS-CoV-2 Spike antibody

    Further determination of Anti-SARS-CoV-2 Spike antibodies in all participants to heterologous/homologous prime-boost immunization of COVID-19 vaccines

    Measured: base line (Day 0) and during the intervention at day 10, 28, 56 and 168 after booster dose of vaccine

  2. Adverse events

    To evaluate the safety of heterologous \& homologous prime-boost immunization of COVID-19 vaccines

    Measured: through study completion, 6 months.

  3. Immunogenicity: Anti-SARS-CoV-2 Nucleocapsid antibody

    Further determination of immunogenicity of Anti-SARS-CoV-2 Nucleocapsid in all participants to heterologous/homologous prime-boost immunization of COVID-19 vaccines.

    Measured: base line (Day 0) and during the intervention at day 10, 28, 56 and 168 after booster dose of vaccine

  4. Immunogenicity: T cell immunity

    Further determination of T cellular immune responses by ELISpot in all participants to heterologous/homologous prime-boost immunization of COVID-19 vaccines.

    Measured: baseline (Day 0) and during the. intervention at day 10 and 28 after booster dose of vaccine

Timeline

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

  1. First posted23 Sep 2021
  2. Study start15 Sep 2021
  3. Primary completion31 Aug 2022
  4. Study completion31 Aug 2022

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
Masking
Single blind
Who is masked
Participant
Enrolment
100 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05054621
Sponsor's protocol ID
Heterologous_AZ_Medigen
Status last verified
Aug 2024
First submitted
13 Sep 2021
Last updated
15 Jun 2026
Results posted
No
FDA-regulated drug
No
FDA-regulated device
No

Publications

  • Chen CJ, Yang LY, Chang WY, Huang YC, Chiu CH, Shih SR, Huang CG, Huang KA. A randomized controlled trial of heterologous ChAdOx1 nCoV-19 and recombinant subunit vaccine MVC-COV1901 against COVID-19. Nat Commun. 2022 Sep 17;13(1):5466. doi: 10.1038/s41467-022-33146-7.

    PubMed 36115850

Questions about this trial

What is this clinical trial studying?

A Phase 2 study testing Heterologous prime-boost schedule with AZD1222 and MVC-COV1901 and Homologous prime-boost schedule with two doses of AZD1222 in people with Covid-19 and Vaccine, run by Chang Gung Memorial Hospital at 1 site in Taiwan.

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 9 inclusion and 11 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 15 Jun 2026. 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 Taiwan. 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?

Immunogenicity: Neutralizing antibody against SARS-CoV-2 (time frame: Day 28 after booster dose). 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 NCT05054621, 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 15 Jun 2026.

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