CompletedPhase 1

A Study on the Safety and Immunogenicity of Influenza, Respiratory Syncytial Virus, Human Metapneumovirus and Parainfluenza Vaccines in Adults 18 to 49 Years of Age.

Australia270 participantsStarted 2025-03-19

Plain-language summary

The objective of this study is to evaluate the safety and immunogenicity of different vaccines of hemagglutinin formulations of trivalent influenza vaccine or of a combined respiratory syncytial virus / human metapneumovirus / parainfluenza virus type 3 vaccine in healthy participants 18 to 49 years of age. A lipid nanoparticle will be used in this study. Overall, the study is designed to: * Assess the safety profile of the candidate formulations * Describe the immunogenicity profile of the candidate formulations * Eligible participants will be randomized to receive a single intramuscular injection of either one of the vaccine formulations. Participants will be provided with a diary to solicit reporting of injection site reactions and systemic reactions, unsolicited Adverse Events (AEs), Serious Adverse Events (SAEs) and Adverse Events of Special Interest AESIs). Participants will also be required to record their daily temperature on the diary.

Who can participate

Age range

18 Years – 49 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion Criteria: * Aged 18 to 49 years on the day of inclusion * A female participant is eligible to participate if she is not pregnant or breastfeeding and one of the following conditions applies: * Is of non-childbearing potential. To be considered of non-childbearing potential, a female must be post-menopausal for at least 1 year, or surgically sterile OR * Is of childbearing potential and agrees to use an effective contraceptive method or abstinence from at least 4 weeks prior to study intervention administration until at least 4 weeks after study intervention administration. Exclusion Criteria: \- Any medical condition or circumstance which, in the opinion of the investigator, might interfere with the evaluation of the study objectives Note: The above information is not intended to contain all considerations relevant to a patient's potential participation in a clinical trial.

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

Presence of any unsolicited systemic Adverse Events (AEs) reported within 30 minutes after vaccination

Timeframe: Within 30 minutes after each vaccination

Presence of solicited injection site and systemic reactions (ie, pre-listed in the participant's diary and in the eCRF (electronic case report form) occurring through 7 days after vaccination

Timeframe: Through 7 days after each vaccination

Presence of unsolicited AEs reported through 28 days after vaccination

Timeframe: Through 28 days after each vaccination

Presence of SAEs (Serious Adverse Events) and AESIs (Adverse Events of Special Interest) throughout the study

Timeframe: Throughout study, approximately 6 months

Presence of out-of-range biological test results (including shift from baseline values) through 7 days after vaccination

Timeframe: Through 7 days after vaccination

Hemagglutinin Inhibition Assay (HAI) antibody (Ab) response to each homologous influenza strain at Day 1 and Day 29

Timeframe: Day 1 and Day 29

Trial details

NCT IDNCT06850051

SponsorSanofi

Sponsor typeINDUSTRY

Study typeINTERVENTIONAL

Primary completion2025-12-11

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