Flu Vaccine for Adults

No longer recruiting at 40 trial locations

Overseen By Trial Transparency email recommended (Toll free for US & Canada)

Age: 18+

Sex: Any

Trial Phase: Phase 1 & 2

Sponsor: Sanofi Pasteur, a Sanofi Company

Must not be taking: Immunosuppressants, Corticosteroids, Anticoagulants, others

Disqualifiers: Immunodeficiency, Myocarditis, GBS, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 1

Duration: 1 day

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial aims to test the safety and effectiveness of new flu vaccines using mRNA technology, similar to some COVID-19 vaccines. It will compare different formulations of these vaccines against standard flu vaccines. The trial seeks adults, 18 years and older, who have not recently received a flu or mRNA vaccine. Participants should be in good health and free of chronic conditions that might interfere with the trial. This study could help improve future flu vaccines for better protection. As a Phase 1 and Phase 2 trial, it focuses on understanding how the treatment works and measuring its effectiveness in an initial, smaller group, offering participants a chance to contribute to groundbreaking research.

Will I have to stop taking my current medications?

The trial does not specify if you need to stop taking your current medications. However, if you are on immunosuppressive therapy or long-term systemic corticosteroids, you may not be eligible to participate.

Is there any evidence suggesting that this trial's treatments are likely to be safe?

Research has shown that Quadrivalent Influenza mRNA vaccines, including MRT5421, MRT5424, and MRT5429, have generally been well-tolerated in past studies. These vaccines aim to protect against four different strains of the flu virus. In trials, healthy adults did not report any major safety issues. However, some mild reactions like fever, dizziness, and muscle pain were noted, usually appearing about two days after vaccination.

The vaccines are currently in the early stages of testing, known as Phase 1 and Phase 2, focusing primarily on safety and the body's response. While these early phases emphasize safety, they don't yet provide complete information on long-term effects. Participants have generally experienced mild side effects, which is common with many vaccines.

Overall, these mRNA flu vaccines have not raised significant safety concerns so far, but ongoing trials will provide more complete safety data as they continue. ^{1 2 3 4 5}

Why are researchers excited about this trial's treatments?

Researchers are excited about these mRNA-based quadrivalent influenza vaccines—MRT5421, MRT5424, and MRT5429—because they represent a new approach to flu prevention. Unlike traditional flu vaccines that use inactivated viruses or protein subunits, these vaccines leverage mRNA technology to instruct cells to produce proteins that trigger an immune response. This method can potentially allow for quicker updates to the vaccine composition in response to emerging flu strains. Additionally, mRNA vaccines have shown the ability to elicit strong and broad immune responses, which could enhance protection against the flu compared to existing options.

What evidence suggests that this trial's treatments could be effective for influenza?

Research has shown that the Quadrivalent Influenza mRNA vaccines, including MRT5421, MRT5424, and MRT5429, studied in this trial, promise strong immune responses. Studies have found that these vaccines can lead to high antibody levels, which help protect against the flu. In animal tests, these vaccines effectively protected against four different flu strains. Some reports suggest an overall vaccine effectiveness of about 39.7%. Early studies in humans also demonstrate strong immune responses, indicating these vaccines could be a good option for flu prevention. ^{1 3 5 6 7}

Are You a Good Fit for This Trial?

Adults aged 18 and older can join this study to test new flu vaccines. People with a history of severe allergic reactions to any vaccine ingredients or who are immunocompromised may not be eligible.

Inclusion Criteria

I am a woman who can have children and have a recent negative pregnancy test.

I am not pregnant or breastfeeding and either cannot have children or will use birth control.

Exclusion Criteria

I have had heart inflammation, nerve issues, or brain swelling in the past.

I have not taken immunosuppressives or long-term steroids in the last 6 months.

Known systemic hypersensitivity to study intervention components; history of life-threatening reaction to study interventions; allergic reaction after administration of mRNA vaccine

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants receive a single intramuscular injection of one of the Quadrivalent Influenza mRNA Vaccines or a control

1 day

1 visit (in-person)

Follow-up

Participants are monitored for safety and immunogenicity, including adverse events and antibody titers

12 months

What Are the Treatments Tested in This Trial?

Interventions

• Quadrivalent Influenza mRNA Vaccine MRT5421
• Quadrivalent Influenza mRNA Vaccine MRT5424
• Quadrivalent Influenza mRNA Vaccine MRT5429

Trial Overview The trial is testing the safety and immune response of three different mRNA flu vaccines against standard dose, high-dose, and recombinant flu vaccines given as a single shot in the muscle.

How Is the Trial Designed?

Group I: Quadrivalent Influenza mRNA Vaccine MRT5429 Dose 4 Experimental Treatment 1 Intervention

participants will receive a single dose of QIV mRNA vaccine MRT5429

Group II: Quadrivalent Influenza mRNA Vaccine MRT5429 Dose 3 Experimental Treatment 1 Intervention

participants will receive a single dose of QIV mRNA vaccine MRT5429

Group III: Quadrivalent Influenza mRNA Vaccine MRT5429 Dose 2 Experimental Treatment 1 Intervention

participants will receive a single dose of QIV mRNA vaccine MRT5429

Group IV: Quadrivalent Influenza mRNA Vaccine MRT5429 Dose 1 Experimental Treatment 1 Intervention

participants will receive a single dose of QIV mRNA vaccine MRT5429

Group V: Quadrivalent Influenza mRNA Vaccine MRT5424 Dose 2 Experimental Treatment 1 Intervention

participants will receive a single dose of QIV mRNA vaccine MRT5424

Group VI: Quadrivalent Influenza mRNA Vaccine MRT5424 Dose 1 Experimental Treatment 1 Intervention

participants will receive a single dose of QIV mRNA vaccine MRT5424

Group VII: Quadrivalent Influenza mRNA Vaccine MRT5421 Dose 1 Experimental Treatment 1 Intervention

participants will receive a single dose of QIV mRNA vaccine MRT5421

Group VIII: Quadrivalent Influenza HD Vaccine Active Control 1 Intervention

participants will receive a single dose of QIV -HD vaccine (for adults ≥ 65 years of age only)

Group IX: Quadrivalent Influenza SD Vaccine Active Control 1 Intervention

participants will receive a single dose of QIV-SD vaccine

Group X: Quadrivalent Influenza RIV4 Vaccine Active Control 1 Intervention

participants will receive a single dose of RIV4 vaccine

Who Is Running the Clinical Trial?

Sanofi Pasteur, a Sanofi Company

Lead Sponsor

Trials

429

Recruited

6,140,000+

Paul Hudson

Sanofi Pasteur, a Sanofi Company

Chief Executive Officer since 2019

Degree in Economics from Manchester Metropolitan University

Dr. Thomas Triomphe

Sanofi Pasteur, a Sanofi Company

Chief Medical Officer since 2020

MD from Tehran University of Medical Sciences

Published Research Related to This Trial

The quadrivalent mRNA-1010 vaccine demonstrated strong humoral immunogenicity, eliciting higher hemagglutination inhibition (HAI) titers against influenza A strains compared to a standard inactivated vaccine, indicating its potential effectiveness in preventing influenza.

No significant safety concerns were reported during the trial, although mild adverse reactions were more common with mRNA-1010, suggesting it is generally safe for use in healthy adults.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Safety and immunogenicity of a phase 1/2 randomized clinical trial of a quadrivalent, mRNA-based seasonal influenza vaccine (mRNA-1010) in healthy adults: interim analysis. Lee, IT., Nachbagauer, R., Ensz, D., et al.[2023]

A quadrivalent mRNA vaccine targeting four seasonal influenza virus strains was shown to induce strong antibody responses in mice, with effective protection against illness even at low doses (as low as 1 μg per antigen).

The mRNA vaccine demonstrated the ability to prevent weight loss and protect against morbidity and mortality from influenza, highlighting its potential as a promising alternative to traditional influenza vaccines.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Seasonal quadrivalent mRNA vaccine prevents and mitigates influenza infection. Kackos, CM., DeBeauchamp, J., Davitt, CJH., et al.[2023]

The quadrivalent influenza vaccine (QIV) demonstrated similar efficacy to the trivalent influenza vaccine (TIV) for the three common strains, but showed superior immunogenicity for the additional B lineages not included in TIV, with significant increases in seroprotection and seroconversion rates.

Both QIV and TIV had comparable safety profiles, with no serious adverse events reported; however, QIV was associated with a slightly higher incidence of injection-site pain.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Immunogenicity and safety of inactivated quadrivalent influenza vaccine in adults: A systematic review and meta-analysis of randomised controlled trials. Moa, AM., Chughtai, AA., Muscatello, DJ., et al.[2018]

The quadrivalent influenza vaccine AdimFlu-S showed strong immunogenicity in a study of 174 healthy children aged 3 to 17, achieving high seroprotection rates above 96.4% for all vaccine strains.

The vaccine was well tolerated with no serious adverse events reported over a 6-month follow-up period, indicating it is a safe option for improving protection against different influenza B lineages.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Immunogenicity and safety of a quadrivalent inactivated influenza vaccine in healthy subjects aged 3 to 17 years old: A phase III, open label, single-arm study. Chang, CY., Cho, CY., Lai, CC., et al.[2021]

The high-dose inactivated influenza vaccine quadrivalent (HD-IIV4) has been shown to be safe and effective in preventing influenza in adults aged 65 and older, with improved immunogenicity against additional B strains compared to standard vaccines.

Despite some increased adverse reactions like injection-site pain and myalgia, HD-IIV4 is recommended as the vaccine of choice for older adults due to its superior efficacy compared to other influenza vaccines.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

High-Dose Inactivated Influenza Vaccine Quadrivalent for Older Adults. Chahine, EB.[2021]

Citations

1. clinicaltrials.gov clinicaltrials.gov/study/NCT06361875

NCT06361875 | A Study to Investigate the Safety and ... The purpose of this study is to evaluate the safety and immunogenicity of a single intramuscular (IM) injection of different formulations of Quadrivalent ...

2. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC10304586/

Moderately Low Effectiveness of the Influenza Quadrivalent ... The overall vaccine effectiveness was moderately low at 39.7%. Phylogenetic analysis revealed that most of the Flu A genotypes in our dataset clustered together ...

3. withpower.com withpower.com/trial/phase-2-influenza-human-3-2024-4332b

Flu Vaccine for Adults · Info for Participants A quadrivalent mRNA vaccine targeting four seasonal influenza virus strains was shown to induce strong antibody responses in mice, with effective protection ...

4. cslseqirus.us cslseqirus.us/news/recently-published-rwe-study-shows-effectiveness-of-cell-based-quad-flu-vaccine-over-3-seasons

Recently Published Real-World Evidence Study Shows ... The study results reveal that the relative vaccine effectiveness of QIVc versus QIVe in prevention of test-confirmed influenza was at least 10% ...

5. ctv.veeva.com ctv.veeva.com/study/a-study-to-investigate-the-safety-and-immunogenicity-of-the-quadrivalent-influenza-mrna-vaccines-in

A Study to Investigate the Safety and Immunogenicity of the ... The purpose of this study is to evaluate the safety and immunogenicity of a single intramuscular (IM) injection of different formulations of Quadrivalent ...

6. clinicaltrials.gov clinicaltrials.gov/study/NCT06361875?term=flublok&cond=influenza&aggFilters=phase:1&viewType=Table&rank=5

A Study to Investigate the Safety and Immunogenicity ... The purpose of this study is to evaluate the safety and immunogenicity of a single intramuscular (IM) injection of different formulations of Quadrivalent ...

7. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC9958848/

Adverse Reactions after BNT162b2 Messenger RNA ... The influenza vaccination passed without any adverse reaction; however, symptoms such as fever, dizziness, and muscle pain emerged at 2 days ...