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Participate in a clinical trial testing a COVID-19 vaccine

Join the ENSEMBLE Study 



There are many COVID-19 vaccine trials recruiting around the country. The study we are recruiting to is called the ENSEMBLE trial.

The ENSEMBLE trial will test the safety and effectiveness of a single-dose, investigational COVID-19 vaccine in adults.

This study is designed to test a single vaccine dose of an investigational COVID-19 vaccine compared with a placebo. The study will include about 60,000 adult volunteers, including many who are older than 60. St. Jude and the University of Tennessee Health Science Center is recruiting about 500 participants in the Memphis area.

Qualified participants will also be reimbursed for reasonable trial-related travel expenses to and from study visits.

You may be eligible to participate if you are:

  • Aged 18 years of age or older
  • In stable health
  • Have not received a prior COVID-19 vaccine

We are looking to enroll people who are more likely to be exposed to COVID-19, including:

  • People with underlying medical conditions
  • People with greater chances of exposure at their job
  • People who live or work in elder-care facilities
  • People over age 65
  • People who work in jails or prisons
  • People from racial and ethnic groups that have been impacted in greater numbers by the COVID-19 pandemic, including people who are African American/Black, Latinx, American Indian, Native Hawaiian and Alaskan Native.

Review Frequently Asked Questions about COVID-19 clinical studies. For specific questions about the ENSEMBLE study being conducted in Memphis, email the study site at  


Before you join the study

You will be asked to fill out an online 5-minute survey to register for the study. You will be asked personal questions to determine if the study is a good match for you. If you are a match, someone will contact you and talk to you about the study and answer any questions you have. If you enter the study, you will get written information about the ENSEMBLE trial. You can talk with other people, like your family or doctor, and take as much time as you need to make the best decision for yourself about whether you want to join the study.

During the study

During the study, you will be asked about your medical history and for blood, saliva and nasal swab samples for necessary lab tests including for COVID-19. At the study site, you will get one injection in the arm, unless otherwise indicated. It will be either the investigational vaccine or a placebo, which is a liquid with no active ingredients. You will keep track of how you feel. Study staff will also be in contact to check on how you are feeling throughout the study.

You will not be exposed to COVID-19 as part of the study. You may still come into contact with the virus in your daily life.

If you develop symptoms of COVID-19 during the study, you will be tested. If you test positive, our study staff will monitor your daily diaries.

There are no costs to you to be in the study. If you are found eligible for the study, you can agree to be in the study now but can change your mind about participation at any time and for any reason.

After the study

When the study is over, we will share the results of the ENSEMBLE trial with you and members of your community, but the names of participants are never shared.

Register for the current study and begin the screening survey. Visit - NCT04505722 for additional details about the ENSEMBLE trial.