for people ages 18 years and up (full criteria)
Healthy Volunteers
healthy people welcome
at UC Davis
study started
estimated completion
Principal Investigator
by Stuart H Cohen (ucdavis)



This is a study to evaluate the effectiveness, immune response, and safety of a coronavirus disease 2019 (COVID-19) vaccine called SARS-CoV-2 rS with Matrix-M1 adjuvant in adults 18 years of age and older in the United States and Mexico. A vaccine causes the body to have an immune response that may help prevent the infection or reduce the severity of symptoms. An adjuvant is something that can make a vaccine work better. This study will look at the protective effect, body's immune response, and safety of SARS-CoV-2 rS with Matrix-M1 adjuvant in the study population. Participants in the study will randomly be assigned to receive SARS-CoV-2 rS with Matrix-M1 adjuvant or placebo. Each participant in the study will receive a total of 2 intramuscular injections over the course of the study. Up to 30,000 participants will take part in the study.

Official Title

A Phase 3, Randomized, Observer-Blinded, Placebo-Controlled Study to Evaluate the Efficacy, Safety, and Immunogenicity of a SARS-CoV-2 Recombinant Spike Protein Nanoparticle Vaccine (SARS-CoV-2 rS) With Matrix-M1™ Adjuvant in Adult Participants ≥ 18 Years


To obtain contact information for a study center near you, please visit:


SARS-CoV Infection Covid19 Coronavirus Prevent-19 Coronavirus Infections Severe Acute Respiratory Syndrome SARS-CoV-2 rS/Matrix-M1 Adjuvant


You can join if…

Open to people ages 18 years and up

  • Adults ≥ 18 years of age at screening who, by virtue of age, race, ethnicity or life circumstances, are considered at substantial risk of exposure to and infection with SARS-CoV-2.
  • Willing and able to give informed consent prior to study enrollment and to comply with study procedures.
  • Participants of childbearing potential (defined as any participant who has experienced menarche and who is NOT surgically sterile [ie, hysterectomy, bilateral tubal ligation, or bilateral oophorectomy] or postmenopausal [defined as amenorrhea at least 12 consecutive months]) must agree to be heterosexually inactive from at least 28 days prior to enrollment and through 3 months after the last vaccination OR agree to consistently use a medically acceptable method of contraception from at least 28 days prior to enrollment and through 3 months after the last vaccination.
  • Is medically stable, as determined by the investigator (based on review of health status, vital signs [to include body temperature], medical history, and targeted physical examination [to include body weight]). Vital signs must be within medically acceptable ranges prior to the first vaccination.
  • Agree to not participate in any other SARS-CoV-2 prevention trial during the study follow-up.

You CAN'T join if...

  • Unstable acute or chronic illness. Criteria for unstable medical conditions include:
  • Substantive changes in chronic prescribed medication (change in class or significant change in dose) in the past 2 months.
  • Currently undergoing workup of undiagnosed illness that could lead to diagnosis of a new condition.
  • Participation in research involving an investigational product (drug/biologic/device) within 45 days prior to first study vaccination.
  • History of a previous laboratory-confirmed diagnosis of SARS-CoV-2 infection or COVID-19.
  • Received influenza vaccination or any other adult vaccine within 4 days prior to or within 7 days after either study vaccination.
  • Autoimmune or immunodeficiency disease/condition (iatrogenic or congenital) requiring ongoing immunomodulatory therapy.
  • Chronic administration (defined as > 14 continuous days) of immunosuppressant, systemic glucocorticoids, or other immune-modifying drugs within 90 days prior to first study vaccination.
  • Received immunoglobulin, blood-derived products, or immunosuppressant drugs within 90 days prior to first study vaccination.
  • Active cancer (malignancy) on therapy within 1 year prior to first study vaccination (with the exception of malignancy cured via excision, at the discretion of the investigator).
  • Any known allergies to products contained in the investigational product.
  • Participants who are breastfeeding, pregnant or who plan to become pregnant within 3 months following last study vaccination.
  • Any other condition that, in the opinion of the investigator, would pose a health risk to the participant if enrolled or could interfere with evaluation of the trial vaccine or interpretation of study results.
  • Study team member or first-degree relative of any study team member (inclusive of Sponsor, and study site personnel involved in the study).
  • Current participation in any other COVID-19 prevention clinical trial.


  • University of California Davis Health accepting new patients
    Sacramento California 95817-2201 United States
  • California Research Foundation accepting new patients
    San Diego California 92123 United States
  • Transitional Research Group, Inc. accepting new patients
    North Hollywood California 91606 United States
  • National Research Institute accepting new patients
    Los Angeles California 90057 United States
  • Dignity Health Medical Foundation - Woodland accepting new patients
    Woodland California 95695 United States

Lead Scientist at UC Health

  • Stuart H Cohen (ucdavis)
    Professor, Infectious Diseases. Authored (or co-authored) 102 research publications.


accepting new patients
Start Date
Completion Date
Phase 3
Study Type
Last Updated