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This trial has completed recruitment on this platform, and is no longer accepting new referrals.

A Respiratory Syncytial Virus (RSV) vaccine clinical trial for older adults

Trial ID: NCT05127434
A research study conducted by Moderna is testing an investigational vaccine that may protect people from RSV. RSV is a common cause of respiratory tract infection and may cause severe disease, especially in younger children and older adults.

Trial Details

The mRNA-1345-P301 study is evaluating the safety and efficacy of an investigational vaccine, called mRNA-1345, to protect against RSV.

RSV can cause infections of the lungs and respiratory tract. Symptoms can be similar to a cold, and may include runny nose, sore throat, cough, and headache. However, RSV can lead to serious conditions like pneumonia especially for younger children and older adults. Currently there is not an approved vaccination for RSV.

Estimated Enrollment

34,000 Participants



Eligibility Criteria

Participants must:

  • Be at least 60 years old
  • Be in generally good health; certain chronic diseases such as heart failure and chronic obstructive pulmonary disease may be permissible
  • Be primarily responsible for self-care (do not require a caretaker)

Participants must not:

  • Have participated in another trial within the past 45 days
  • Have received a vaccination or donated blood in the past month

What to Expect

Sites are located in the cities/states identified with the red pin:

The total length of participation in this clinical trial is approximately 2 years (25 months). It includes up to 8 trial visits and 26 brief communications (via telephone, email, or text message). You may have the option for some of the trial visits to be completed at home with a mobile health provider or through a video visit. Your trial doctor will discuss these options with you.

  • Clinical trial volunteers will have a screening visit to check whether they are eligible to participate. If they are eligible and choose to participate, they will have 7 more trial visits over the next 2 years.
  • Clinical trial participants will be given one injection in the upper arm
  • Each clinical trial participant has a 50% chance of receiving the investigational vaccine and a 50% chance of receiving the placebo – like flipping a coin.
    • A placebo does not contain any active ingredients

Participation in the mRNA-1345-P301 study lasts approximately two years and includes phone calls, telemedicine visits, and up to eight visits to the study site.

  • You will be given one injection in the upper arm. You have a chance of receiving either the mRNA-1345 study vaccine or the placebo. By using a placebo, medical researchers are able to understand if the study vaccine is effective in generating high levels of antibodies against RSV.
  • After the study injection, you will be asked to return to the study site five to six times over the next year. You will have one telemedicine visit with the study doctor after each injection to monitor for any symptoms. During these phone calls, the study doctor and medical staff will check how you are feeling and ask for updates on your health.
  • You will be asked to use an eDiary app on your smartphone or a provided smartphone to report any symptoms you might experience 7 days after vaccination.
  • You will be closely monitored by the study clinic team if any symptoms are reported at any time throughout your participation.

Insurance is not needed to join this clinical trial, and compensation for your time will be available.

Frequently Asked Questions (FAQs)