This trial is not actively recruiting.

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

PREVENT-19: A COVID-19 vaccine candidate clinical trial

Novavax initiated the PREVENT-19 trial to evaluate the safety, efficacy and immunogenicity of NVX-CoV2373, our vaccine candidate designed to provide protection against COVID-19 disease.

Trial ID:


Novavax’ Commitment to Diversity & Inclusion

This COVID-19 clinical trial is testing whether the investigational vaccine, NVX-CoV2373 will prevent COVID-19.

COVID-19 is a global health crisis, and safe and effective vaccines are critical to ending the pandemic.

The PREVENT-19 (PRE-fusion protein subunit Vaccine Efficacy Novavax Trial | COVID-19) clinical trial will enroll up to 30,000 adults in approximately 115 locations in the U.S. and Mexico to test whether the investigational vaccine candidate, NVX-CoV2373, will prevent COVID-19 disease. It will compare this investigational vaccine with a placebo vaccine, a substance that contains no actual medication. It will also test it for safety and immunogenicity.

Different populations may respond differently to medical interventions. To address this, we designed PREVENT-19 to include people from different races and ethnicities as well as those with underlying medical conditions to ensure that the vaccine is safe and effective for everyone. PREVENT-19 aims to include members of the Black/African American, Latinx, and Native American communities.

The study is also focused on including people living with medical conditions commonly associated with complications arising from COVID-19 disease (e.g., obesity, chronic kidney or lung disease, cardiovascular disease and Type 2 diabetes), and those over the age of 65.

Click here to learn more about NVX-CoV2373, receive updates or access trial protocols and a fact sheet.

We want you to participate!

Prevent-19 At A Glance


~30,000 adults 18+ in the U.S. and Mexico


Older adults (65+) and diverse racial and ethnic populations


Two-thirds of participants will initially receive the investigational vaccine


Determine efficacy and assess safety in prevention of COVID-19 disease

Trial Details

This COVID-19 clinical trial is studying whether the investigational vaccine NVX-CoV2373 will prevent COVID-19 disease. It will compare this vaccine candidate with a placebo, a substance that contains no actual medication.

Participants who qualify for the study will receive:

  • Study-related medical tests throughout the clinical trial
  • The study vaccine or placebo
  • Study-related monitoring of health and follow-up care
  • You may be compensated for participating in this clinical trial.

Eligibility Criteria

Participants must:
  • Be 18 years of age and older
  • Have never tested positive for COVID-19
  • Have a greater risk of becoming infected with COVID-19. Examples include:

    Examples include:

    • Represent a racial and ethnic group that has been greatly impacted by the pandemic such as African American, Latinx, Native American
    • Live in crowded conditions, such as shared housing
    • Working in close contact with the public or other workers including "essential work" settings: healthcare facilities, public safety or transportation, farms, factories, grocery stores, restaurants and daycares
    • You have underlying medical conditions
    • You are 65 or older
Participants are not eligible if they:
  • Have tested positive for COVID-19
  • Are pregnant of breastfeeding
  • Have participated in another clinical trial in the past month

What’s involved in participating in this clinical trial

Participation in the PREVENT-19 trial is divided into three (3) periods


First, the study team will determine if you are eligible to take part in the study. Get started with this questionnaire.


If you are selected to participate, you will get two (2) injections of the investigational vaccine or placebo - one on the first day and a second again three (3) weeks (21 days) later.


The study team will monitor your health for two (2) years after the last injection.

You will be randomly assigned (by chance) to receive either the investigational vaccine or placebo. A placebo does not contain any actual medication. Neither you nor the study doctor will know which group you are in or which injections you receive. Each participant has a two (2) in three (3) chance of receiving the investigational vaccine and a one (1) in three (3) chance of receiving the placebo.


You will need to travel to one of our sites to take part in this clinical trial.
Sites are located in the cities/states identified with the red pin:

Frequently Asked Questions (FAQ)


Novavax is grateful to the tens of thousands of trial participants around the world who are volunteering for our vaccine studies. We thank Operation Warp Speed (OWS) and the Coalition for Epidemic Preparedness Innovations (CEPI) for their significant support of our work.