Study to Evaluate the Safety of a Lyophilized RSV mRNA Vaccine

A Randomized, Double-Blind, Placebo-Controlled Phase I Clinical Trial to Evaluate the Safety of Different Doses of a Lyophilized RSV mRNA Vaccine in Adults Aged 18 Years and Older

To evaluate the safety of Sinovac RSV mRNA among participants aged ≥18 years

Study Overview

• Status: Not yet recruiting
• Conditions: RSV; mRNA Vaccine
• Intervention / Treatment: Biological: Low-dose RSV mRNA vaccine; Biological: High-dose RSV mRNA vaccine; Other: Placebo

Detailed Description

This is a randomized, double-blind, placebo-controlled clinical trial, enrolling a total of 60 participants aged ≥18 years. Eligible participants will be enrolled sequentially by age (18~49 → ≥50 years old) and dosage (low → High), and then be randomized to the study group and the control group in a ratio of 2:1. Sentinel participant will be set. All participants were required to complete immediate reaction observation within 30 minutes after each vaccine dose, and adverse events until 30 days after vaccination, as well as serious adverse events and adverse event of special interest throughout the whole study period.

• Study Type: Interventional
• Enrollment (Estimated): 60
• Phase: Phase 1

Contacts and Locations

• Study Contact: Name: Weimin Zhao, Dr.; Phone Number: +86 13934135335; Email: 283282678@qq.com

Study Locations

• China
  • Shanxi
    • Changzhi, Shanxi, China
      • Qinxian Center for Disease Control and Prevention
      • Contact: Zhiqiang Niu; Phone Number: +86 15536180156; Email: ltby_8966@qq.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

1. Participants can understand and voluntarily sign the informed consent form;
2. Able to provide legal identity documents;
3. Healthy individuals aged 18 years and above;
4. Participants of childbearing potential and their sexual partners voluntarily adopt effective contraceptive measures (such as correct use of condoms, or female participants using combined oral contraceptives, intrauterine devices) from the time the participant signs the informed consent form until 6 months after the administration of the investigational vaccine, and have no plans to donate sperm or ovums; Female participants of childbearing potential must also have adopted effective contraceptive measures within 2 weeks before enrollment.

Exclusion Criteria:

Participants who meet any of the following criteria will be excluded from this trial:

1. Those with fever on the day of vaccination with the trial vaccine, with an axillary temperature > 37.0℃ before vaccination;
2. Those with a history of previous RSV vaccination, or a history of RSV infection within 6 months before enrollment.
3. Known to be allergic to vaccines or vaccine components;
4. Before vaccination, the electrocardiogram examination and clinical laboratory test indicators specified in the protocol are abnormal and clinically significant;
5. Female participants who are breastfeeding or pregnant;
6. Having autoimmune diseases or immunodeficiency diseases (including but not limited to systemic lupus erythematosus, ankylosing spondylitis, autoimmune thyroid diseases, asplenia, functional asplenia, splenectomy, HIV infection);
7. History of poorly controlled chronic diseases or severe diseases, including but not limited to cardiovascular diseases (such as hypertension uncontrolled by drugs, i.e., systolic blood pressure ≥ 140 mmHg and/or diastolic blood pressure ≥ 90 mmHg for participants aged 18-59 years old, systolic blood pressure ≥ 150 mmHg and/or diastolic blood pressure ≥ 100 mmHg for participants aged 60 years old and above, as well as congenital heart disease, atrial fibrillation, myocarditis, pericarditis), hematological system diseases, liver and kidney diseases, respiratory system diseases, malignant tumors, history of transplantation of major functional organs, or any other diseases or physiological conditions that the researcher believes can interfere with the trial results;
8. Current encephalopathy (such as damage to cerebral nerve tissue caused by congenital hypoplasia of the brain, brain trauma, brain tumors, cerebral hemorrhage, brain infection, chemical drug poisoning, etc.);
9. Severe neurological diseases, such as a history of demyelinating diseases including but not limited to Guillain-Barré syndrome, multiple sclerosis, neuromyelitis optica, acute disseminated encephalomyelitis, etc., or a history of convulsions, epilepsy, or a family history of mental illness;
10. Having a doctor-diagnosed coagulation dysfunction (such as coagulation factor deficiency, coagulative diseases, abnormal platelets);
11. Having received systemic immunosuppressive agents or other immunomodulatory treatments (prednisone [≥ 20 mg/day] or its equivalent) for ≥ 14 days within the past 3 months, cytotoxic therapy, or planning to receive such treatments during the study period;
12. Having received immunoglobulin or other blood products within 3 months before receiving the trial vaccine, or planning to receive such treatments during the study period;
13. Currently participating in other clinical trials, or planning to receive such drugs or vaccines during the study period;
14. Having received live attenuated vaccines within the past 14 days or other vaccines with processes such as subunit or inactivated vaccines within 7 days;
15. Having various acute diseases or acute exacerbation of chronic diseases within the past 7 days, or known or suspected active infection;
16. Axillary temperature > 37.0℃ within the past 3 days, or use of anti-allergic drugs, non-steroidal antipyretic analgesics, etc.;
17. Those with skin damage, inflammation, ulceration, rash, scarring, or other conditions at the target vaccination site that may interfere with vaccination or observation of local reactions;
18. According to the researcher's judgment, participants have any other factors that make them unsuitable for participating in the clinical trial.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Sinovac RSV mRNA vaccine low-dose group; Participants will receive one dose of low-dose lyophilized RSV mRNA vaccine.	Biological: Low-dose RSV mRNA vaccine; One dose of RSV mRNA vaccine in low dosage
Experimental: Sinovac RSV mRNA vaccine high-dose group; Participants will receive one dose of high-dose lyophilized RSV mRNA vaccine.	Biological: High-dose RSV mRNA vaccine; One dose of RSV mRNA vaccine in high dosage
Placebo Comparator: Placebo control group; Participants will receive one dose of normal saline.	Other: Placebo; Participants will receive one dose of normal saline.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Incidence of adverse events	Up to 30 days after vaccination

Secondary Outcome Measures

Outcome Measure	Time Frame
Incidence of adverse events	Up to 14 days after vaccination
Incidence of serious adverse events and adverse events of special interest	Up to 12 months after vaccination

Collaborators and Investigators

• Sponsor: Sinovac Biotech Co., Ltd

Study record dates

Study Major Dates

• Study Start (Estimated): March 9, 2026
• Primary Completion (Estimated): June 30, 2026
• Study Completion (Estimated): May 30, 2027

Study Registration Dates

• First Submitted: February 11, 2026
• First Submitted That Met QC Criteria: February 11, 2026
• First Posted (Actual): February 18, 2026

Study Record Updates

• Last Update Posted (Actual): February 18, 2026
• Last Update Submitted That Met QC Criteria: February 11, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: RSV vaccine
• Other Study ID Numbers: PRO-mRSV-1001

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No