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What is a clinical trial?

Health care workers answer questions about the COVID-19 vaccines.


Valerie Montgomery Rice, MD explains what clinical trials are in the COVID vaccine development process and why are they safe.


Clinical research trial is when we take volunteers and ask them to participate in a study. And it can be a study where we are trying to test a new drug or to test a vaccine. It is totally voluntary, and it has an end point.

The most important thing about a clinical trial is, first of all, whatever we’re doing it has to first pass the safety test. And then we’ve already done in a clinical trial, we’ve already done early studies to give us an indication of its effectiveness.

So, by the time something gets to a phase three trial, we know the safety and we know the dose, okay? We know how much you need to use and we know that it’s safe to use that amount.

Now what we’re doing is we’re giving it to volunteers and we’re giving it to a diverse group enough of volunteers, that we can look for unanticipated side effects and effectiveness across a diverse spectrum of people.

This information is shared for educational purposes only and should not be used as a substitute for professional medical advice. The views expressed are those of the featured medical professional and reflect information available to that professional at time of filming. Always consult a health care provider for any personal health decisions. Click here for vaccine FAQs from the CDC.

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