Fact Check: 7 Persistent Myths about COVID-19 Vaccines

Anesthesiologist Anoushka Afonso receiving a COVID-19 vaccine.

MSK anesthesiologist Anoushka Afonso receives a COVID-19 vaccine from clinical nurse Janine Guerra.

Myth: The mRNA vaccines change your DNA and could cause cancer.

Truth: None of the vaccines interact with or alter your DNA in any way, and therefore cannot cause cancer.

Messenger RNA (mRNA) is not the same as DNA and cannot be combined with DNA to change your genetic code. Here’s now mRNA vaccines actually work:

The mRNA vaccines use a tiny piece of the coronavirus’ genetic code to teach your immune system how to make a protein that will trigger an immune response if you get infected. The mRNA is fragile, so after it delivers the instructions to your cells, it breaks down and disappears from the body (in about 72 hours). The mRNA never even goes into the nucleus of the cell — the part that contains your DNA.

Therefore, there is no truth to the myth that somehow the mRNA vaccine could inactivate the genes that suppress tumors.

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Myth: If I’m not at risk for severe COVID-19 complications, I don’t need the vaccine.

Truth: Healthy people can develop severe COVID-19 infection. Even though they are at a lower risk for severe COVID-19 complications, they can contract and spread the virus. Getting vaccinated protects you as well as your community.

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Myth: Getting immunity naturally is safer than getting it from a vaccine.

Truth: The amount of natural immunity a person gets after an infection varies from person to person. Early evidence suggests that natural immunity may not last very long, according to the Centers for Disease Control and Prevention (CDC). Developing immunity from the vaccine is less risky than developing immunity naturally because there’s no way to predict the severity of your symptoms if you get COVID-19.

We expect that when 70% of the population has either received the vaccine or been infected, we will reach what is called “herd immunity,” meaning the chances of the virus still circulating are very low. Waiting until this number is reached naturally — without vaccinating the public — will keep COVID-19 around for much longer.

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Myth: Getting vaccinated will make me sick.

Truth: The vaccine does not contain any live or inactive portion of the COVID-19 virus. It will not cause you to test positive on a test that looks for active COVID-19 infection. Some people receiving the vaccines have reported mild to moderate side effects, including pain at the injection site, fatigue (feeling tired), headache, and muscle pain. Not everyone gets side effects. But if you do, they are normal and a sign your body is building up its defenses against the virus.

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Myth: The vaccines were developed too quickly. We can’t be sure they are safe.

Truth: COVID-19 vaccines were developed rapidly compared with earlier vaccines because scientists, doctors, and government agencies all over the world invested massive resources to cut red tape and publish results as soon as they were available.

As of August 16, 2021, more than 168 million Americans have been fully vaccinated and the CDC continues to track all adverse reactions.

Read about the safety of the COVID-19 vaccines »

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Myth: The vaccines aren’t safe for people who are pregnant or are trying to get pregnant.

Truth: The CDC notes that pregnant women are at increased risk for severe illness from COVID-19. On August 11, 2021, the CDC recommended that pregnant people be vaccinated, based on the agency’s review of recent vaccine safety data. This new guidance follows a previous recommendation from the American College of Obstetricians and Gynecologists (ACOG). 

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Myth: The death toll from COVID-19 is exaggerated. It includes people who were already sick with other conditions.

Truth: In a report from the CDC on deaths due to COVID-19, researchers found COVID-19 can directly and indirectly lead to mortality. People with underlying conditions like diabetes or obesity are at higher risk for contracting COVID-19 than those without preexisting conditions. It is true that a person’s preexisting condition may have contributed to their death from COVID-19. However, if the person had not contracted the virus, it is unlikely their preexisting condition would have led to their death. The death toll from COVID-19, in fact, is likely higher than what current numbers indicate. People who die from COVID-19 without being tested, for example, may not be included in current counts.


August 16, 2021


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