Can you get COVID after being vaccinated?
Reviewed by Steve Silvestro, MD, Ro,
Written by Chimene Richa, MD
last updated: Dec 03, 2021
2 min read
Here's what we'll cover
The short answer is yes, you can get COVID after being vaccinated.
The clinical trials on these vaccines showed that they effectively prevented COVID-19 disease—94.5% effectiveness for the Moderna vaccine and 95% effectiveness for the Pfizer-BioNTech vaccine (Oliver, 2020). The clinical trials measured effectiveness by looking at how many people developed the COVID-19 disease after receiving the vaccine and compared them to people who caught COVID-19 without being vaccinated.
While these rates are impressive, it's still possible that you could be infected with the coronavirus virus and pass it on to others unknowingly, especially if you never develop symptoms. If you do get COVID after being vaccinated, you’re much more likely to have a mild course of illness. While mask mandates seem to be going in and out of style, and with the rise of different variants that may require additional vaccines, it's important to take precautions and avoid exposing at-risk people to the coronavirus, even if you have received the vaccine.
How does the COVID-19 vaccine work?
Millions of people in the U.S. and worldwide have received vaccines to prevent COVID-19. The mRNA vaccines currently available in the United States carry genetic blueprints for the spike proteins that line the virus’s outer capsule. After you get the vaccine, your cells take the blueprints and make replica viral spike proteins, which trigger your immune system to produce antibodies against future infection. If you are exposed to the COVID-19 virus in the future, your body is armed and ready to attack the virus before it can make you sick.
Can you get COVID-19 from the vaccine?
You cannot get COVID-19 from the vaccine—just like you can’t put together a 300-piece puzzle with only one piece. The COVID-19 mRNA vaccines only contain the genetic blueprints that allow your body’s cells to make only one piece of the virus—the viral spike proteins. That’s it. There are not enough parts of the virus included in the vaccine for you to get sick with COVID-19.
Some people experience side effects after receiving the vaccine, like arm soreness where they got the injection, fatigue, headaches, muscle aches, and even fever. These are not symptoms of being ill with COVID-19. They are signs that your immune system is responding to the viral proteins.
DISCLAIMER
If you have any medical questions or concerns, please talk to your healthcare provider. The articles on Health Guide are underpinned by peer-reviewed research and information drawn from medical societies and governmental agencies. However, they are not a substitute for professional medical advice, diagnosis, or treatment.
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Centers for Disease Control and Prevention (CDC). (2020, December). Symptoms of Coronavirus. Retrieved on Feb. 5, 2021 from https://www.cdc.gov/coronavirus/2019-ncov/symptoms-testing/symptoms.html
Oliver, S., Gargano, J., Marin, M., Wallace, M., Curran, K. G., Chamberland, M., et al. (2020). The Advisory Committee on Immunization Practices’ Interim Recommendation for Use of Pfizer-BioNTech COVID-19 Vaccine — United States, December 2020. MMWR Morbidity and Mortality Weekly Report; 69 :1922-1924. doi: 10.15585. Retrieved on Aug. 23, 2021 from https://www.cdc.gov/mmwr/volumes/69/wr/mm6950e2.htm?s_cid=mm6950e2_w
U.S. Food and Drug Administration (FDA) (2020a, December) Vaccines and Related Biological Products Advisory Committee Meeting - FDA Briefing Document: Moderna COVID-19 Vaccine. Retrieved on Feb. 5, 2021 from https://www.fda.gov/media/144434/download
U.S. Food and Drug Administration (FDA) (2020b, December) Vaccines and Related Biological Products Advisory Committee Meeting - FDA Briefing Document: Pfizer-BioNTech COVID-19 Vaccine. Retrieved on Feb. 5, 2021 from https://www.fda.gov/media/144245/download
Woolf, S. H., Chapman, D. A., & Lee, J. H. (2021). COVID-19 as the Leading Cause of Death in the United States. JAMA, 325 (2): 123–124. doi: 10.1001/jama.2020.24865. Retrieved from https://jamanetwork.com/journals/jama/fullarticle/2774465
How we reviewed this article
Current version
Chimene Richa, MD
Steve Silvestro, MD
About the medical reviewer
