NCT07819097 · Pfizer
A Study to Learn About the Safety and Immune Responses of RSVpreF in Older Adults
What this study is about
The purpose of this study is to learn about the safety, tolerability, and immune response of the RSVpreF vaccine in healthy older adults. Participants will take part in this study for about 6 months. The study will include people in China and the United States. In China, participants will receive either RSVpreF or placebo.
View original scientific description
The purpose of this study is to learn about the safety, tolerability, and immune response of the RSVpreF vaccine in healthy older adults. Participants will take part in this study for about 6 months. The study will include people in China and the United States. In China, participants will receive either RSVpreF or placebo. A placebo is a dummy vaccine with no active ingredient, but it looks just like the vaccine being studied. In the United States, all participants will receive RSVpreF. Researchers will check for any reactions. They will also check blood test results to learn how the body responds to the vaccine. The main questions the study aims to answer are: * What local reactions and systemic events (body-wide symptoms) do participants have after a RSVpreF vaccination? * What medical problems do participants have after a RSVpreF vaccination? * Researchers will compare antibody levels from blood tests between the China cohort and the US cohort. An antibody is a substance in the body that try to fight off an infection or foreign substance. Participants will: * Have a screening visit to make sure they qualify for the study (participants in China will have this visit before the day of vaccination) * Receive the RSVpreF vaccination (or a placebo injection if in the China cohort) once at Visit 1. * Have a telephone or clinic visit 1 week later to assess local reactions and systemic events. * Have a clinic visit a month after vaccination for a checkup and tests. * Have a telephone or clinic visit 6 months after vaccination for a health check. * Have a blood test at screening (if in the China cohort only), on the day of vaccination and 1 month after vaccination.
Interventions
BIOLOGICAL
RSVpreF
Single Dose
OTHER
Placebo
Single Dose
Primary outcome measures
Percentage of participants reporting local reactions: pain at the injection site, redness, and swelling
Time frame: Within 7 days after vaccination
Percentage of participants reporting systemic events: fever, fatigue, headache, vomiting, nausea, diarrhea, muscle pain, and joint pain
Time frame: Within 7 days after vaccination
Percentage of participants reporting adverse events (AEs)
Time frame: Within 1 month after vaccination
Percentage of participants reporting serious adverse events (SAEs)
Time frame: Through 6 months after vaccination
Percentage of participants reporting newly diagnosed chronic medical conditions (NDCMCs)
Time frame: Through 6 months after vaccination
RSV A and RSV B neutralizing antibody levels before vaccination and 1 month after vaccination
Time frame: Before vaccination and 1 month after vaccination
Geometric mean fold rise in RSV A and RSV B neutralizing antibody levels from before vaccination to 1 month after vaccination
Time frame: Before vaccination to 1 month after vaccination
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Participants 60 years of age or older at enrolment.
- Healthy participants, or participants with stable long-term medical conditions, if the investigator decides they can take part.
- Adults who can walk and live in the community or in assisted-living/long-term care settings with minimal help.
- Participants who can give signed informed consent and follow study visits and procedures, including the 7-day electronic diary and blood tests. Key
Exclusion criteria
- Confirmed RSV infection 180 days or less before study vaccination.
- Any past history of Guillain-Barré syndrome.
- Severe reaction to a vaccine or severe allergy to a study vaccine component or related vaccine.
- Serious or unstable medical condition that the investigator believes makes the study unsafe.
- Immunocompromised status, based on medical history and/or examination.
- Previous receipt of any licensed or investigational RSV vaccine or RSV preventive monoclonal antibody, or planned receipt during the study. Please refer to the study contact for further eligibility details Contacts/Locations Central Contact Person: Pfizer CT.gov Call Center Telephone: 1-800-718-1021 Email: ClinicalTrials.gov\_Inquiries@pfizer.com
Where
- Scottsdale, Arizona
- Lake Forest, California
- Riverside, California
- Milford, Connecticut
- Washington D.C., District of Columbia
- Meridian, Idaho
- Evansville, Indiana
- Warren Township, New Jersey
- Columbus, Ohio
- Philadelphia, Pennsylvania
- Draper, Utah
- South Jordan, Utah
And 2 more locations — see the full list below.
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Oct 9, 2026 · Source of record for eligibility and locations