UW Vaccine & Treatment Evaluation Unit

July 12, 2021

Updated 7/12/2021: “Mix ‘n Match” Booster COVID-19 Vaccine Clinical Trial

Adults Needed for UW COVID-19 Vaccine Booster Clinical Trial

The University of Washington is seeking volunteers for a Phase 1/2 COVID-19 vaccine booster trial.  The purpose of this clinical trial is to test the safety and effectiveness of additional doses of EUA vaccines, or boosts, in people who have received an EUA vaccine series.

The study will enroll two groups: 

  • Group 1: Participants who have completed an EUA vaccine series at least 12 weeks prior to joining the study.  People who have completed the 2-dose Pfizer or Moderna series or the 1-dose Janssen (also known as Johnson & Johnson or J&J) series may be eligible.  
  • Group 2: Participants who have not received any EUA vaccine previously.  This group will receive the 2-shot Moderna series as part of the study, and may receive a booster shot later.

For both groups, the trial will last for about one year and will involve at least 7-11 in-person visits depending on your group.

Participants will undergo a screening assessment to see whether they are eligible. Study visits will involve physical exams, blood draws, and vaccine injections.  Participants will be asked to keep a diary of their vaccine reactions for 7-days after each injection. 

To be eligible for the trial you must:

  • Be 18 years of age or older
  • Have received an EUA vaccine no less than 12 weeks ago (Group 1)
  • Be willing to receive an EUA vaccine, in addition to the booster (Group 2)

Conditions which would prevent you from participating:

  • Previous SARS-CoV-2 infection
  • Current pregnancy or breastfeeding
  • Serious reactions to vaccines


For completing the entire study, participants in Group 1 will be compensated $800, while those in Group 2 will be compensated $1400.

Clinic Location: Our clinic is located on the 11th floor of the Ninth and Jefferson Building at Harborview Medical Center. We are open Monday through Friday 8am to 6pm.

Please contact us at 206-520-4366 or email us at joinuwcovid19vax@uw.edu for more information. You can also find more information on the NIH’s webpage for this clinical trial.