COVID-19 Vaccines

Understanding COVID-19 Vaccines

Which COVID-19 vaccines are available in the United States? 

On September 11, 2023, the U.S. Food and Drug Administration (FDA) updated the emergency use authorizations for two mRNA COVID-19 vaccines. The updated vaccines are composed of a formula that provides extra protection against currently circulating variants. Both vaccines are authorized for anyone who is at least six months old.

• Moderna COVID-19 Vaccine, 2023-2024 Formula: This vaccine is an updated version of the NIH-funded, FDA-approved mRNA-1273 vaccine (Spikevax) that has more activity against the Omicron XBB.1.5 strain View the infographic to see what is in the original Moderna COVID-19 vaccine.

• Pfizer, Inc., and BioNTech COVID-19 Vaccine, 2023-2024 Formula: This vaccine is an updated version of the FDA-approved BNT162b2 vaccine (Comirnaty) that has more activity against the Omicron XBB.1.5 strain. View the infographic to see what is in the original Pfizer COVID-19 vaccine.

Two other COVID-19 vaccines have been authorized for certain groups.

• Novavax COVID-19 Vaccine, Adjuvanted: On July 13, 2022, the FDA reauthorized emergency use of this two-dose vaccine series for people age 12 and older. This is the first protein-based COVID-19 vaccine to receive FDA authorization and is similar in design to vaccines against the flu and shingles. The FDA has also authorized Novavax as a booster vaccination for people age 18 and older who cannot access other COVID-19 vaccines, people for whom other COVID-19 vaccines are not clinically appropriate, or people who would not otherwise receive a COVID-19 vaccine.

• Janssen Pharmaceutical Companies of Johnson & Johnson:  On March 13, 2023, the FDA reauthorized emergency use of this vaccine for use in people 18 and older who cannot access other COVID-19 vaccines, people for whom other COVID-19 vaccines are not clinically appropriate, or people who would not otherwise receive a COVID-19 vaccine.

Do I need an updated COVID-19 vaccine?

Protection against SARS-CoV-2 begins to decrease over time after a person’s first vaccine doses — the primary vaccine series. For the best protection from COVID-19, the Centers for Disease Control and Prevention (CDC) recommends that everyone 6 months and older stay up to date on their COVID-19 vaccines, including getting updated vaccine doses if eligible.

Updated versions of COVID-19 vaccines may be authorized each year to provide extra protection against new, common viral variants. People who are 65 or older or who are immunocompromised may need more booster doses.

Can children get a vaccine?

Children and teens age 6 months and older can get the updated Pfizer and Moderna COVID-19 vaccines, and children and teens age 12 and older can get the Novavax COVID-19 vaccine.

Do the vaccines protect against virus variants? 

Studies and current data show that the antibodies our bodies make after vaccination recognize and protect against COVID-19 variants like Omicron. However, studies also show that the protection against variants offered by the original COVID-19 vaccines wanes substantially over time. The updated mRNA vaccines offer increased protection against SARS-CoV-2 infection and severe COVID-19.