COVID-19 vaccines give your body instructions to learn what the coronavirus looks like. Then your body breaks down the vaccine and flushes it out. If you catch the virus later, your body can recognize it and attack it right away. You’re less likely to get seriously sick because your body is prepared.

The vaccines don’t contain any live coronavirus, so they can’t give you the disease. After getting vaccinated, you might feel tired, have a sore arm, or run a fever for a day or two. That’s normal—it means your body is building up protection.

While vaccines may not keep you from getting infected, they can save your life. Healthy people of any age can develop severe and long-lasting symptoms, with higher risk if you are living with obesity, diabetes, or high blood pressure. Most people who have recently been hospitalized from COVID-19 have not gotten vaccinated. And if you’ve already had the virus, vaccines can help protect you if you get sick again.

Thousands of volunteers of different ages, races, ethnicities, and communities helped researchers make sure the vaccines are safe for everyone. Millions more around the world have now safely received the vaccines. When you get vaccinated, doctors closely watch for rare, unintended effects. There’s no evidence that vaccines affect your ability to have children. Overall, the risks of COVID-19 are much more serious than the risks of the vaccines.