Skip to main content

Health library

COVID-19 vaccines. Get the facts.

Reviewed 2/19/2024

COVID-19 vaccines: Get the facts

As you consider getting vaccinated for COVID-19, you may have questions. You might even feel nervous. That's OK.

Learning the facts about the COVID-19 vaccines can help you make a good choice for you, your family and your community.

Here's a look at some common COVID-19 vaccine myths and facts.

MYTH: Getting a COVID-19 vaccine can make me sick with COVID-19.

None of the current U.S. vaccines contain the live virus that causes COVID-19. Instead, the vaccines teach your immune system how to recognize and fight the virus. This keeps you from getting sick with COVID-19.

FACT: The vaccines are very effective at stopping COVID-19.

All of the recommended vaccines have been shown to work well in preventing COVID-19. And if you do get the coronavirus, these vaccines lower your risk of getting very sick. Booster shots help keep that protection strong.

MYTH: I've had COVID-19, so I don't need a vaccination.

Having COVID-19 gives you natural immunity to the disease, but health experts don't know how long natural immunity lasts. A vaccine can add to your protection. So even if you've had COVID-19, you should still get vaccinated.

MYTH: The COVID-19 vaccines will alter my DNA.

The vaccines will not have any effect on your DNA at all. The Pfizer-BioNTech and Moderna vaccines contain messenger RNA (mRNA). The mRNA teaches your cells how to make a protein from the coronavirus. That prompts your immune system to create antibodies which fight the virus that causes COVID-19. But the mRNA never enters the nucleus of your cells, which is where DNA is found. It never interacts with your DNA in any way.

FACT: The vaccines do not affect a woman's ability to have a baby.

There is currently no evidence that the antibodies formed after COVID-19 vaccination cause any problems with pregnancy. In fact, there is no evidence that fertility problems are a side effect of any vaccine.

FACT: The vaccines are safe for most people with allergies.

COVID-19 vaccines are recommended for people 6 months and older, including people with food or medication allergies. If you’ve had an allergic reaction to a vaccine in the past, you are allergic to the ingredients in a COVID-19 vaccine or if you had a reaction to your first dose, talk to your doctor. They can help you choose a vaccine that will be safe for you.

MYTH: The vaccine is only for adults.

Everyone 6 months and older is eligible for a COVID-19 vaccine. Ask your provider, your local pharmacy or your health department how to make an appointment. Make sure to stay up-to-date with boosters too.

MYTH: The vaccines were developed too fast to know if they're really safe or not.

All of the authorized vaccines were tested first in rigorous clinical trials. Vaccines, including the COVID-19 vaccines, go through three phases of clinical trials before they can be authorized for the public. To help speed the development of the COVID-19 vaccines, the schedule of those phases overlapped. And vaccines were made in advance to speed distribution. That saved time, but it did not cut corners.

All of the authorized vaccines met tough standards from the Centers for Disease Control and Prevention and the U.S. Food and Drug Administration (FDA).

The vaccines have also undergone the most intense safety monitoring in United States history. Multiple systems continue to track the vaccines to detect problems. Millions of Americans have been safely vaccinated, and serious problems are rare.

FACT: The side effects of the vaccines are minor.

Some, but not all, people have temporary side effects after being vaccinated. Side effects people have reported include:

  • Pain at the injection site.
  • Body aches.
  • Headaches.
  • Fever.

These side effects only last for a day or two. They are signs that your body is building immunity against the virus. You should call your doctor if symptoms last more than a few days.

Want to learn more about COVID-19 vaccines?

Explore our Coronavirus health topic center.

Related stories