General Information

COVID-19 Vaccine - General Information

Below are frequently asked questions related to COVID-19 vaccine general information. Click on another category to the left to see more FAQs.

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There are three updated COVID-19 vaccines recommended by the U.S. Centers for Disease Control (CDC):

  • The Pfizer-BioNTech vaccine has full FDA approval for people 12 and older. Additionally, it is authorized for emergency use in children ages 5 through 11 years old and 6 months through 4 years old.
  • The Moderna vaccine has full FDA approval for people 18 and older. It is authorized for emergency use in people ages 6 months to 18 years.
  • People 12 years and older who are unable or choose not to get an updated Pfizer-BioNTech or Moderna COVID-19 vaccine can consider the updated Novavax COVID-19 vaccine. 

J&J/Janssen COVID-19 vaccine, a viral vector vaccine, has expired and is no longer available for use in the United States as of May 6, 2023.

The original two-dose series of the monovalent vaccine is no longer recommended for people in the United States. A single updated shot is now the recommended protection.

The updated mRNA vaccines created by Pfizer-BioNTech and Moderna are monovalent, as opposed to the bivalent vaccines from 2022. That means they’re intended to protect against just one variant: XBB.1.5, a more recent offspring of Omicron that surfaced in early 2023.

All three vaccines are given as an injection into the muscle. The single shot of the updated vaccine is recommended regardless of whether someone has previously completed the primary two-dose series.

A second dose of the updated vaccine, administered no sooner than four months after the initial dose, is available to adults 65 and older, and to people who are immunocompromised.

SARS-CoV-2 is the virus that causes COVID-19. The vaccines increase the body’s immune response by making antibodies. These antibodies block the SARS-CoV-2 virus from injecting itself into human cells, thereby preventing it from reproducing and making you sick.

There are several SARS-CoV-2 variants that scientists are actively tracking, some of which have caused increased transmissibility and increased disease severity. In some cases, antibodies developed from previous infection or vaccination are less able to neutralize these variants and prevent infection.

The latest vaccines have been modified to incorporate a monovalent (single) component that protects against the Omicron variant XBB.1.5. This aligns with available data and advice from the FDA's expert advisers.

No. You cannot become infected with SARS-CoV-2, the virus that causes COVID-19, from any of the vaccines.

The ingredients for the Pfizer-BioNTech COVID-19 vaccine, the Moderna COVID-19 vaccine and the Novavax COVID-19, adjuvanted vaccine are listed on the FDA website. None of the vaccines contain the live virus that causes COVID-19, eggs, preservatives or mercury.

The Pfizer and Moderna vaccines use the same mRNA technology, but contain different ingredients to protect the mRNA, maintain the pH, and stabilize the solution. The ingredients include:

  • Messenger RNA (mRNA) – the active ingredient that causes your body to produce antibodies
  • Lipids – these create the fatty shell that protects the mRNA as it is stored, administered and delivered to cells
  • Salts, sugar and other compounds – to maintain the proper pH balance and stabilize the vaccine

The Novavax COVID-19, adjuvanted vaccine is a protein subunit vaccine. It contains pieces (proteins) of the virus that causes COVID-19 and another ingredient called an adjuvant. These components teach your immune system how to recognize and respond quickly if infected with the actual virus spike protein. The ingredients include:

  • Protein – the SARS-CoV-2 recombinant spike protein that creates an immune response to help protect your body from getting infected with COVID-19 in the future
  • Lipids - cholesterol and phosphatidylcholine, which help the spike protein enter cells
  • Adjuvant – helps activate the cells in the immune system
  • Salts, sugars and acids – to maintain the proper pH balance and stabilize the vaccine

While no longer approved for use or distributed in the United States, the Johnson & Johnson vaccine used what’s known as “viral vector” technology. This means a harmless cold virus, adenovirus 26 (Ad26), was engineered to contain the gene for the SARS-CoV-2 “spike” protein. It also contained salts, sugar and buffers to maintain the pH and stabilize the solution. The ingredients included:

  • Recombinant, replication-incompetent adenovirus type 26 expressing the SARS-CoV-2 spike protein - the active ingredient that causes your body to produce antibodies
  • Salts, sugar and other compounds - to maintain the pH balance and stabilize the vaccine. Full ingredient list: Citric acid monohydrate, trisodium citrate dihydrate, ethanol, 2-hydroxypropyl-β-cyclodextrin (HBCD), polysorbate-80, sodium chloride.

COVID-19 has killed more than one million people in the United States. This is significantly more deaths than other viruses that we routinely vaccinate against, such as influenza, which typically causes 12,000 to 52,000 deaths in the U.S. per year, according to the CDC.

In addition to the high death toll, COVID-19 can also cause other long-term complications. The COVID-19 vaccine saves lives and decreases the likelihood of long term COVID-related problems involving the brain, heart and lungs.

COVID-19 infections, hospitalizations and death rates are disproportionately higher in lower-income communities and communities of color. Vaccines are needed to stop the virus and prevent COVID-19’s devastating health, social and financial effects on lower-income communities of color.

It depends on the setting. Now that the Pfizer and Moderna vaccines have full FDA approval, it’s easier for schools, employers, and the military to mandate COVID-19 vaccination for students and employees. Check with your employer or school for more information.

Even in settings where the COVID-19 vaccine is not mandated, it is highly encouraged that anyone eligible receive the vaccine, as it is the best way to protect yourself and those around you.