Under section 564 of the Federal Food, Drug, and Cosmetic Act (FD&C Act), the FDA Commissioner may allow unapproved medical products or unapproved uses of approved medical products to be used in an emergency to diagnose, treat, or prevent serious or life-threatening diseases or conditions caused by chemical, biological, radiological or nuclear threat agents when there are no adequate, approved, and available alternatives. Vaccines that receive an EUA may later be fully licensed by the FDA.
Ask the Experts: COVID-19: Vaccine Products
No. Only the updated (2023–2024 Formula) COVID-19 vaccines are currently authorized or approved for use in the United States.
Moderna COVID-19 Vaccine has two updated (2023–2024 Formula) presentations. CDC has summarized basic information about the different presentations and their storage, preparation, and administration in its Moderna COVID-19 vaccine at-a-glance document available here: www.cdc.gov/vaccines/covid-19/info-by-product/moderna/downloads/vaccine-at-a-glance.pdf.
Vaccinators who stock multiple presentations should check three times to confirm that they are administering the proper product with the proper dose and dose volume for each patient.
Both the Pfizer-BioNTech COVID-19 Vaccine and the Moderna COVID-19 Vaccine are lipid nanoparticle-formulated, nucleoside-modified mRNA vaccines encoding the prefusion spike glycoprotein of SARS-CoV-2, the virus that causes COVID-19. The 2023–2024 formula targets the Omicron XBB.1.5 sublineage of the spike protein. Visit this CDC website for more details about how mRNA vaccines work: https://www.cdc.gov/coronavirus/2019-ncov/vaccines/different-vaccines/how-they-work.html.
The original COVID-19 vaccines all targeted the spike protein of the original SARS-CoV-2 virus. The current vaccines target the spike protein of a more recently circulating strain, known as the Omicron XBB.1.5 sublineage. The update is intended to boost production of antibodies that protect more effectively against disease caused by currently circulating Omicron subvariants.
The process of updating the strain without changing anything else is similar to the seasonal strain changes made for influenza vaccinations each year; FDA does not require manufacturers to repeat the large-scale clinical trials necessary for the original products before authorizing updated vaccines. Vaccine safety, side effects, and risk of allergic reactions are expected to be comparable to the original vaccines of the same brand and dose. As with seasonal influenza vaccines, future COVID-19 vaccines can continue to be updated when needed, as the circulating viruses evolve.
No. The last U.S. doses of Janssen COVID-19 Vaccine expired May 7, 2023.
Novavax COVID-19 Vaccine, Adjuvanted contains the Omicron XBB.1.5 subvariant SARS-CoV-2 spike protein and Matrix-M adjuvant. The saponin-based adjuvant is made from extracts of the bark of the Soapbark tree native to Chile. It is added to enhance the immune response of the vaccine recipient. The spike protein is produced in insect cells.
It is authorized for emergency use in people age 12 years or older as a two-dose primary series for previously unvaccinated individuals (whether or not they are immunocompromised), with the doses given at least 3 to 8 weeks apart. Individuals who have had one or more doses of any previous authorized or approved COVID-19 vaccine formulation are recommended to receive only one dose of the current formulation. Individuals with moderate or severe immunocompromise may receive additional doses as determined by their healthcare team, based on their specific circumstances.
The effectiveness of Novavax COVID-19 Vaccine against currently circulating variants of SARS-CoV-2 is not precisely known. Clinical trials of this vaccine were conducted against earlier variants no longer in circulation; however, the vaccine showed very good effectiveness against moderate to severe disease during clinical trials. Testing conducted on antibodies in the serum of Novavax vaccine recipients suggests that vaccination provides substantial protection against severe disease and death caused by currently circulating variants, consistent with other available COVID-19 vaccines.
CDC has developed a “one-stop” product-specific webpage for each COVID-19 vaccine with all of the important details that immunization providers need to know: www.cdc.gov/vaccines/covid-19/info-by-product/index.html.