What is the COVID-19 vaccine made of? mRNA explained

The first COVID-19 vaccines authorized for use in the U.S. are what’s called messenger RNA vaccines, also referred to as mRNA vaccines. These vaccines have proven 94-95% effective at preventing the COVID-19 virus and are a crucial step to keeping you, your family and our communities safe.

But we get it — while researchers have been studying and working with mRNA vaccines for decades, these vaccines are new to you. You have questions. You want to know what they are made of, what to expect, and most importantly, if they’re safe. (More on that here.)

So, let’s dive into what mRNA is and how these COVID-19 vaccines are made.

First, a strand of mRNA is created from the DNA of the virus. Don’t let this scare you — while some other vaccines are “live” vaccines that put a weakened or inactivated germ into our bodies, the COVID-19 vaccine is not one of them. mRNA vaccines do not use the live virus that causes COVID-19.

Rather, mRNA vaccines work by teaching your cells how to make a protein, or even just a piece of a protein, that triggers an immune response in your body. That immune response protects you from getting infected if the real virus enters your body. And that’s the point of the vaccine — to help your body make antibodies that learn to fight this small portion of the virus without getting truly sick. Then, when you do encounter COVID-19 and it tries to infect you, your body will be quick to respond with its own lifesaving antibodies.

Wondering what to expect when you get the COVID-19 vaccine? Here’s a look at the vaccination process, from start to finish. To learn more about mRNA vaccines, refer to this CDC resource. You can also find answers to frequently asked questions on our dedicated COVID-19 vaccine page.