Keeping Our Study Participants Safe

An infographic describing what happens during a study safety pause. The text below fully describes the graphic content.
Credit: Lisa Donohue, CoVPN

What Happens During a Study Safety Pause?

The safety and well-being of our study participants is our top priority. This means that we may pause an entire study because of something that happens to one person in the study.

Adverse events, even serious ones, are normal in research studies. And the more people participating in a study, the more events can be expected to occur. When a study pauses, this is not cause for alarm. It shows that the safety monitoring systems are working to protect study participants. This also helps to ensure the safety of the general public when the study products are approved and made available.

What Is an Adverse Event?

  • Mild event (e.g., injection site soreness)
  • Severe event (e.g., hospitalization)

An adverse event is something negative or harmful that might happen to a person enrolled in the study. These events may or may not be related to the study vaccine, antibody, or placebo. They might be as simple as mild side effects, like having a sore arm after getting an injection or infusion, or twisting your ankle when leaving the clinic. ALL events, big and small, are important to us.

Protecting Confidentiality

Safety and the privacy of our participants are our TOP priorities. When people join our studies we commit to do everything we can to keep their information safe from the outside world. Their data may be shared with safety review groups but their identity will not. We CAN share general information about safety events with the public but we CANNOT share a lot of information because of our promise to protect our participants’ confidentiality.


Prior to Study Start

To start, studies need national groups, like the US Food and Drug Administration (FDA), to approve the rules for study pauses. Study rules are approved by regulatory groups.

Study Begins

A study can start when the study rules (the protocol) are approved. Participants receive study product or placebo.

Adverse Event Occurs

If something negative or harmful happens to a person in the study, no matter how big or small, it is evaluated. It only takes one serious adverse event to pause a study.

Study Pause

If an event is considered severe, several actions are taken to ensure safety and protect participant confidentiality.

  1. Participant monitored
  2. Injections/infusions stop
  3. Confidential DSMB review of unblinded data
  4. Study participants notified
  5. Communicate to public

Data Safety & Monitoring Board Reviews Event

The DSMB (an independent review group) has access to unblinded information to help them assess each event and determine if it is caused by the study product. DSMB directs whether the study can continue.

Study Resumes

Participants are informed of the details of the adverse event. They can consider whether they want to continue in the study (re-consent). Participants have the option to resume participating in study.

Content last reviewed on May 12, 2021