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There are two types of COVID-19 vaccines licensed or authorized in the United States. None of the COVID-19 vaccines are preferred over another when more than one licensed or authorized, recommended, and age-appropriate vaccine is available.
Pfizer-BioNTech and Moderna COVID-19 vaccines are mRNA vaccines. mRNA vaccines use mRNA created in a laboratory to teach our cells how to make a protein—or even just a piece of a protein—that triggers an immune response inside our bodies. The mRNA from the vaccines is broken down within a few days after vaccination and discarded from the body.
As of September 12, 2023, the 2023–2024 updated Pfizer-BioNTech and Moderna COVID-19 vaccines were recommended by CDC for use in the United States.
Novavax COVID-19 vaccine is a protein subunit vaccine. Protein subunit vaccines contain pieces (proteins) of the virus that causes COVID-19. The virus pieces are the spike protein. The Novavax COVID-19 vaccine contains another ingredient called an adjuvant. It helps the immune system respond to that spike protein. After learning how to respond to the spike protein, the immune system will be able to respond quickly to the actual virus spike protein and protect you against COVID-19.
As of October 3, 2023, the 2023-2024 updated Novavax COVID-19 Vaccine, Adjuvanted was recommended by CDC for use in the United States for people aged 12 years and older.
The 2023–2024 updated COVID-19 vaccines more closely targets the XBB lineage of the Omicron variant and could restore protection against severe COVID-19 that may have decreased over time.
The manufacturers use different ingredients in the vaccines. None of the vaccines contain eggs, gelatin, latex, or preservatives. After the body produces an immune response, it discards all of the vaccine ingredients, just as it would discard any substance that cells no longer need. This process is a part of normal body functioning.
Find a full list of ingredients and information on the conditions of use, storage and handling, preparation, and administration procedures in the COVID-19 vaccine-specific package inserts and FDA fact sheets and U.S. COVID-19 Vaccine Product Information.
None of the COVID-19 vaccines affect or interact with our DNA and the following are not included in the vaccines:
CDC recommends that people receive the age-appropriate COVID-19 vaccine product and dosage based on their age on the day of vaccination. COVID-19 vaccine dose amounts are different for different age groups. COVID-19 vaccine doses and timing are different for people who are moderately or severely immunocompromised.
These vaccines are given by the intramuscular route, which means they are given as a shot in the muscle of the upper arm or in the thigh of a young child.
COVID-19 vaccines have undergone—and will continue to undergo—the most intensive safety monitoring in U.S. history. Evidence from the hundreds of millions of COVID-19 vaccines already administered in the United States, and the billions of vaccines administered globally, demonstrates that they are safe and effective.
Side Effects
Adverse Events
Learn more about vaccine safety monitoring after a vaccine is authorized or approved for use.