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Coronavirus: Explaining the vaccine approval process

Here's a look at how vaccines get approved, according to the CDC.

AUSTIN, Texas — There is a lot riding on a vaccine for COVID-19. So here is a look at how the Centers for Disease Control and Prevention (CDC) says vaccines get approved.

To start, each vaccine must go through three phases before being approved. The first involves 20 to 100 healthy volunteers. 

Researchers here are looking for some basic things:

  • Does the vaccine work?
  • Is it safe?
  • Are there serious side effects?
  • Does the dosage affect those side effects?

The second phase involves several hundred volunteers. Here, researchers are looking for the most common short-term side effects and how the volunteers' immune systems seem to be responding.

RELATED: UT researchers stay on campus to continue coronavirus work, inching closer to a vaccine

The third phase requires hundreds or thousands of volunteers. This is where researchers are looking for how people who get the vaccine compare to those who do not.

The only way a vaccine gets approved is if it's safe and effective and if the benefits outweigh the risks.

There is at least one vaccine heading into this third phase next month. It is a trial that will involve 30,000 people, so it could take months to sift through all of the data that will be gathered.


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