COVID-19Phase 4DAN-COMBONCT07790523
Effectiveness of An Influenza/COVID-19 Vaccine (mCombriax [mRNA-1083]) in Adults ≥ 65 Years
A Phase 4 study testing mCombriax® (mRNA-1083) and Efluelda® (TIV-HD) and Spikevax® (mRNA-1273) in people with COVID-19 and Influenza, run by Tor Biering-Sørensen at 3 sites in 2 countries.
Trial summary
The purpose of this pragmatic randomized trials is to evaluate the comparative vaccine effectiveness (cVE) of mCombriax® (mRNA-1083) versus same day co-administration of the active comparators (i.e., high-dose influenza vaccine/Efluelda® and mRNA-1273/Spikevax®) among adults aged 65 years and older. Read more about this study
- Who is it for?
- Ages 65 years and olderHealthy volunteers can take part
- What is being tested?
- mCombriax® (mRNA-1083) and Efluelda® (TIV-HD) and Spikevax® (mRNA-1273)
- Type of treatment
- Vaccines
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 410,000 participants
- Where
- 3 sitesin 2 countries
- Study dates
- 1 Sep 2026to 30 Sep 2028
- Phase
- Phase 4
- Are there results?
- Not yet: the study is under way
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 65 years and older
- All sexes
- Healthy volunteers accepted
- Older adult
Who may be able to join
- Age ≥65 years at the time of vaccination
- Self-reported ability to understand written and spoken English or Danish (Denmark only) or Spanish or Galician (Spain only)
- Informed consent form has been signed and dated
Who cannot join
- There are no specific exclusion criteria for this study
Trial locations and contacts
3 sites in 2 countries. Contact the study team or a site near you to ask about taking part.
3 sites in 2 countries
Denmark2 sites
Center for Translational Cardiology and Pragmatic Randomized Trials, Department of Cardiology, Copenhagen University Hospital - Herlev and Gentofte
Hellerup, 2900
Lisa S Duus, +4540639843, lisa.steen.duus@regionh.dk
Tor Biering-Sørensen, +4528933590, tor.biering-soerensen@regionh.dk
Danske Lægers Vaccinations Service
Søborg, 2860
Carsten S Larsen, +4540459708, carslars@rm.dk
Carsten S Larsen, MD, DMSc
Spain1 site
General Public Health Directorate of Galician Health Service
Santiago de Compostela, A Coruña
Carmen Rodríguez-Tenreiro-Sánche, 655 299 502, carmentenreiro@hotmail.es
Federico M Torres, MD, PhD
About this study
Official title: A Phase 4, Pragmatic, Randomized Trial to Evaluate the Effectiveness of An Influenza/COVID-19 Vaccine (mCombriax [mRNA-1083]) in Adults ≥ 65 Years
The purpose of this pragmatic randomized trials is to evaluate the comparative vaccine effectiveness (cVE) of mCombriax® (mRNA-1083) versus same day co-administration of the active comparators (i.e., high-dose influenza vaccine/Efluelda® and mRNA-1273/Spikevax®) among adults aged 65 years and older.
Read the detailed description
This Phase 4 randomized, active-comparator, pragmatic trial is designed to evaluate the effectiveness of a seasonal variant-containing formulation of mCombriax® (mRNA-1083) compared with same-day co-administration of authorized standalone enhanced influenza and COVID-19 vaccines in adults aged ≥65 years. The trial is designed to be conducted over two consecutive respiratory virus seasons to account for potential seasonal variation in virus circulation, vaccine composition, and effectiveness. The primary objective is to evaluate the comparative vaccine effectiveness (cVE) of the combination vaccine with respect to clinically relevant outcomes, including severe influenza and COVID-19. Demonstration of non-inferior protection in real-world setting, in combination with the potential programmatic advantages of a single-dose strategy, may support policy recommendations, reimbursement decisions, and broader implementation of combined seasonal respiratory vaccination strategies.
- Being tested
- mCombriax® (mRNA-1083), Efluelda® (TIV-HD) and Spikevax® (mRNA-1273)
- Keywords
- COVID-19, Influenza, mCombriax, Pragmatic, Registry, Respiratory tract disease, Cardiovascular, Hospitalization, Vaccination
- Medical subject headings
- COVID-19, Influenza, Human, Respiratory Tract Diseases
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
mCombriax® (mRNA-1083)Biological
An authorized mRNA-based multicomponent vaccine encoding antigens targeting both seasonal influenza and SARS-CoV-2 viruses.
Efluelda® (TIV-HD) and Spikevax® (mRNA-1273)Biological
Same-day co-administration of an authorized high-dose trivalent influenza vaccine (TIV-HD; Efluelda®) and an authorized COVID-19 mRNA vaccine (Spikevax®, mRNA-1273)
| Study group | Role | What they receive |
|---|---|---|
| mCombriax® (mRNA-1083) | Experimental | An authorized mRNA-based multicomponent vaccine encoding antigens targeting both seasonal influenza and SARS-CoV-2 viruses. Receives: Biological: mCombriax® (mRNA-1083) |
| Efluelda® (TIV-HD) and Spikevax® (mRNA-1273) | Active comparator | Same-day co-administration of an authorized high-dose trivalent influenza vaccine (TIV-HD; Efluelda®) and an authorized COVID-19 mRNA vaccine (Spikevax®, mRNA-1273) Receives: Biological: Efluelda® (TIV-HD) and Spikevax® (mRNA-1273) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Medically attended influenza and/or COVID-19
Defined as a laboratory-confirmed positive influenza A/B test or positive SARS-CoV-2 test, regardless of healthcare setting, or influenza-related or COVID-19-related hospitalization, defined by ICD-10 codes.
Measured: From Day 14 after vaccination through the end of follow-up, up to 8 months after vaccination
Influenza and/or COVID-19 hospitalization
Defined as hospitalization with a relevant ICD-10 code for influenza or COVID-19 infection or any hospitalization with a laboratory-confirmed positive influenza A/B test or SARS-CoV-2 test performed within 7 days prior to hospitalization or within 48 hours of hospital admission.
Measured: From Day 14 after vaccination through the end of follow-up, up to 8 months after vaccination
Secondary outcomes (7)
Medically attended influenza
Measured: From Day 14 after vaccination through the end of follow-up, up to 8 months after vaccination
Influenza hospitalization
Measured: From Day 14 after vaccination through the end of follow-up, up to 8 months after vaccination
Medically attended COVID-19
Measured: From Day 14 after vaccination through the end of follow-up, up to 8 months after vaccination
COVID-19 hospitalization
Measured: From Day 14 after vaccination through the end of follow-up, up to 8 months after vaccination
All-cause cardio-respiratory hospitalization
Measured: From Day 14 after vaccination through the end of follow-up, up to 8 months after vaccination
All-cause respiratory tract disease hospitalization
Measured: From Day 14 after vaccination through the end of follow-up, up to 8 months after vaccination
All-cause hospitalization
Measured: From Day 14 after vaccination through the end of follow-up, up to 8 months after vaccination
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted27 Aug 2026
- Study start1 Sep 2026 (estimated)
- Primary completion31 May 2028 (estimated)
- Study completion30 Sep 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for COVID-19Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
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 4
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 410,000 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Tor Biering-Sørensen
- Sponsor type
- University, hospital or other
- Collaborators
- ModernaTX, Inc.
- Responsible party
- Sponsor-investigator, Tor Biering-Sørensen, Herlev and Gentofte Hospital
- Investigators
- Tor Biering-Sørensen, Study chair, Center for Translational Cardiology and Pragmatic Randomized Trials, Department of Cardiology, Copenhagen University Hospital - Herlev and Gentofte
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07790523
- Sponsor's protocol ID
- DAN-COMBO
- Other IDs
- 2026-526720-49-00
- Acronym
- DAN-COMBO
- Status last verified
- Aug 2026
- First submitted
- 21 Aug 2026
- Last updated
- 27 Aug 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: In this trial, baseline and endpoint data will be collected from Danish administrative health registries, which are subject to Danish legislation and can only be made available to a third party under certain conditions. Please contact the sponsor-investigator in case of any inquiries.
Study at a glance
From the registry record, last updated by the sponsor on 27 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase 4, Pragmatic, Randomized Trial to Evaluate the Effectiveness of An Influenza/COVID-19 Vaccine (mCombriax [mRNA-1083]) in Adults ≥ 65 Years
- ClinicalTrials.gov ID
- NCT07790523
- Acronym / sponsor ID
- DAN-COMBO / DAN-COMBO
- Keywords
- COVID-19, Influenza, mCombriax, Pragmatic, Registry, Respiratory tract disease, Cardiovascular, Hospitalization
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 410,000 participants (estimated)
- Lead sponsor
- Tor Biering-SørensenUniversity, hospital or other
- Collaborators
- ModernaTX, Inc.
- Study start
- 1 Sep 2026 (estimated)
- Primary completion
- 31 May 2028 (estimated)
- Study completion
- 30 Sep 2028 (estimated)
- First posted
- 27 Aug 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of this pragmatic randomized trials is to evaluate the comparative vaccine effectiveness (cVE) of mCombriax® (mRNA-1083) versus same day co-administration of the active comparators (i.e., high-dose influenza vaccine/Efluelda® and mRNA-1273/Spikevax®) among adults aged 65 years and older.
Detailed description
This Phase 4 randomized, active-comparator, pragmatic trial is designed to evaluate the effectiveness of a seasonal variant-containing formulation of mCombriax® (mRNA-1083) compared with same-day co-administration of authorized standalone enhanced influenza and COVID-19 vaccines in adults aged ≥65 years. The trial is designed to be conducted over two consecutive respiratory virus seasons to account for potential seasonal variation in virus circulation, vaccine composition, and effectiveness. The primary objective is to evaluate the comparative vaccine effectiveness (cVE) of the combination vaccine with respect to clinically relevant outcomes, including severe influenza and COVID-19. Demonstration of non-inferior protection in real-world setting, in combination with the potential programmatic advantages of a single-dose strategy, may support policy recommendations, reimbursement decisions, and broader implementation of combined seasonal respiratory vaccination strategies.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| mCombriax® (mRNA-1083) | Experimental | Biological: mCombriax® (mRNA-1083)An authorized mRNA-based multicomponent vaccine encoding antigens targeting both seasonal influenza and SARS-CoV-2 viruses. |
| Efluelda® (TIV-HD) and Spikevax® (mRNA-1273) | Active comparator | Biological: Efluelda® (TIV-HD) and Spikevax® (mRNA-1273)Same-day co-administration of an authorized high-dose trivalent influenza vaccine (TIV-HD; Efluelda®) and an authorized COVID-19 mRNA vaccine (Spikevax®, mRNA-1273) |
Who may qualify
- Ages
- 65 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Older adult
Key inclusion criteria (3 listed)
- Age ≥65 years at the time of vaccination
- Self-reported ability to understand written and spoken English or Danish (Denmark only) or Spanish or Galician (Spain only)
- Informed consent form has been signed and dated
Key exclusion criteria (1 listed)
- There are no specific exclusion criteria for this study
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| mCombriax® (mRNA-1083)An authorized mRNA-based multicomponent vaccine encoding antigens targeting both seasonal influenza and SARS-CoV-2 viruses. | Biological | mCombriax® (mRNA-1083) |
| Efluelda® (TIV-HD) and Spikevax® (mRNA-1273)Same-day co-administration of an authorized high-dose trivalent influenza vaccine (TIV-HD; Efluelda®) and an authorized COVID-19 mRNA vaccine (Spikevax®, mRNA-1273) | Biological | Efluelda® (TIV-HD) and Spikevax® (mRNA-1273) |
Primary outcome
Medically attended influenza and/or COVID-19
Time frame: From Day 14 after vaccination through the end of follow-up, up to 8 months after vaccination
Defined as a laboratory-confirmed positive influenza A/B test or positive SARS-CoV-2 test, regardless of healthcare setting, or influenza-related or COVID-19-related hospitalization, defined by ICD-10 codes.
Influenza and/or COVID-19 hospitalization
Time frame: From Day 14 after vaccination through the end of follow-up, up to 8 months after vaccination
Defined as hospitalization with a relevant ICD-10 code for influenza or COVID-19 infection or any hospitalization with a laboratory-confirmed positive influenza A/B test or SARS-CoV-2 test performed within 7 days prior to hospitalization or within 48 hours of hospital admission.
7 secondary outcomes
Medically attended influenza
Time frame: From Day 14 after vaccination through the end of follow-up, up to 8 months after vaccination
Influenza hospitalization
Time frame: From Day 14 after vaccination through the end of follow-up, up to 8 months after vaccination
Medically attended COVID-19
Time frame: From Day 14 after vaccination through the end of follow-up, up to 8 months after vaccination
COVID-19 hospitalization
Time frame: From Day 14 after vaccination through the end of follow-up, up to 8 months after vaccination
All-cause cardio-respiratory hospitalization
Time frame: From Day 14 after vaccination through the end of follow-up, up to 8 months after vaccination
All-cause respiratory tract disease hospitalization
Time frame: From Day 14 after vaccination through the end of follow-up, up to 8 months after vaccination
All-cause hospitalization
Time frame: From Day 14 after vaccination through the end of follow-up, up to 8 months after vaccination
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 27 Aug 2026.
- Individual participant dataSharing planned: Yes. In this trial, baseline and endpoint data will be collected from Danish administrative health registries, which are subject to Danish legislation and can only be made available to a third party under certain conditions. Please contact the sponsor-investigator in case of any inquiries.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Tor Biering-Sørensen study chair
Center for Translational Cardiology and Pragmatic Randomized Trials, Department of Cardiology, Copenhagen University Hospital - Herlev and Gentofte
3 sites in 2 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing mCombriax® (mRNA-1083) and Efluelda® (TIV-HD) and Spikevax® (mRNA-1273) in people with COVID-19 and Influenza, run by Tor Biering-Sørensen at 3 sites in 2 countries.
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 3 inclusion and 1 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: opening soon, as of the sponsor's last update on 27 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 3 sites in Denmark, Spain. 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 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Lisa S Duus (+4540639843, lisa.steen.duus@regionh.dk), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Medically attended influenza and/or COVID-19 (time frame: From Day 14 after vaccination through the end of follow-up, up to 8 months after vaccination). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 27 Aug 2026.