Important update: Healthcare facilities
CDC has updated select ways to operate healthcare systems effectively in response to COVID-19 vaccination. Learn more
To maximize protection from the Delta variant and prevent possibly spreading it to others, get vaccinated as soon as you can and wear a mask indoors in public if you are in an area of substantial or high transmission.
UPDATE
Given new evidence on the B.1.617.2 (Delta) variant, CDC has updated the guidance for fully vaccinated people. CDC recommends universal indoor masking for all teachers, staff, students, and visitors to K-12 schools, regardless of vaccination status. Children should return to full-time in-person learning in the fall with layered prevention strategies in place.
UPDATE
The White House announced that vaccines will be required for international travelers coming into the United States, with an effective date of November 8, 2021. For purposes of entry into the United States, vaccines accepted will include FDA approved or authorized and WHO Emergency Use Listing vaccines. More information is available here.
UPDATE
Travel requirements to enter the United States are changing, starting November 8, 2021. More information is available here.

Moderna COVID-19 Vaccine Overview and Safety

Moderna COVID-19 Vaccine Overview and Safety
CDC has expanded recommendations for booster shots to now include all adults ages 18 years and older who received a Pfizer-BioNTech or Moderna (mRNA) COVID-19 vaccine as part of their primary series. Get more information and read CDC’s media statement.

General Information

Name: mRNA-1273

Manufacturer: ModernaTX, Inc.

Type of Vaccine: mRNA

Number of Shots: 2 shots, 28 days apart
Some immunocompromised people should get 3 shots.

Booster Shot: Some groups of people are recommended to get a booster shot at least 6 months after getting their second shot. You can get any of the COVID-19 vaccines authorized in the United States for your booster shot.

How Given: Shot in the muscle of the upper arm

Does NOT Contain: Eggs, preservatives, latex, metals
See Full List of Ingredients Below

Who Should Get Vaccinated
Who Should NOT Get Vaccinated
  • If you have had a severe allergic reaction (anaphylaxis) or an immediate allergic reaction, even if it was not severe, to any ingredient in an mRNA COVID-19 vaccine (such as polyethylene glycol), you should not get an mRNA COVID-19 vaccine.
  • If you had a severe or immediate allergic reaction after getting the first dose of an mRNA COVID-19 vaccine, you should not get a second dose of either of the mRNA COVID-19 vaccines (Moderna or Pfizer-BioNTech).
  • An immediate allergic reaction means a reaction within 4 hours of getting the shot, including symptoms such as hives, swelling, or wheezing (respiratory distress).

If you aren’t able to get an mRNA COVID-19 vaccine, you may still be able to get a different type of COVID-19 vaccine. Get more information for people with allergies.

Moderna COVID-19 Vaccine Ingredients

All COVID-19 vaccine ingredients are safe. Nearly all of the ingredients in COVID-19 vaccines are ingredients found in many foods – fats, sugars, and salts. The Moderna COVID-19 vaccine also contains a harmless piece of messenger RNA (mRNA). The COVID-19 mRNA teaches cells in the body how to create an effective immune response to the virus that causes COVID-19. This response helps protect you from getting sick with COVID-19 in the future. After the body produces an immune response, it discards all of the vaccine ingredients, just as it would discard any information that cells no longer need. This process is a part of normal body functioning.

All COVID-19 vaccines are manufactured with as few ingredients as possible and with very small amounts of each ingredient. Each ingredient in the vaccine serves a specific purpose as seen in the table below.

Full list of ingredients

The Moderna COVID-19 Vaccine contains the following ingredients:

Type of Ingredient

Ingredient

Purpose

Type of Ingredient

Messenger ribonucleic acid (mRNA)

Ingredient

  • Nucleoside-modified mRNA encoding the viral spike (S) glycoprotein of SARS-CoV-2

Purpose

Provides instructions the body uses to build a harmless piece of a protein from the virus that causes COVID-19. This protein causes an immune response that helps protect the body from getting sick with COVID-19 in the future.

Type of Ingredient

Lipids (fats)

Ingredient

  • PEG2000-DMG: 1,2-dimyristoyl-rac-glycerol, methoxypolyethylene glycol
  • 1,2-distearoyl-sn-glycero-3-phosphocholine
  • BotaniChol® (non-animal origin cholesterol)
  • SM-102: heptadecane-9-yl 8-((2-hydroxyethyl) (6-oxo-6-(undecyloxy) hexyl) amino) octanoate

Purpose

Work together to help the mRNA enter cells.

Type of Ingredient

Salt, sugar, acid stabilizers, and acid

Ingredient

  • Sodium acetate
  • Sucrose (basic table sugar)
  • Tromethamine
  • Tromethamine hydrochloride
  • Acetic acid (the main ingredient in white household vinegar)

Purpose

Work together to help keep the vaccine molecules stable while the vaccine is manufactured, frozen, shipped, and stored until it is ready to be given to a vaccine recipient.

Messenger ribonucleic acid (mRNA):
Nucleoside-modified mRNA encoding the viral spike (S) glycoprotein of SARS-CoV-2

Purpose
Provides instructions the body uses to build a harmless piece of a protein from the virus that causes COVID-19. This protein causes an immune response that helps to protect the body from getting sick with COVID-19 in the future.

Lipids (fats):

  • PEG2000-DMG: 1,2-dimyristoyl-rac-glycerol, methoxypolyethylene glycol
  • 1,2-distearoyl-sn-glycero-3-phosphocholine
  • BotaniChol® (non-animal origin cholesterol)
  • SM-102: heptadecane-9-yl 8-((2-hydroxyethyl) (6-oxo-6-(undecyloxy) hexyl) amino) octanoate

Purpose
Work together to help the mRNA enter cells

Salt, sugar, acid stabilizers, and acid:

  • Sodium acetate
  • Sucrose (basic table sugar)
  • Tromethamine
  • Tromethamine hydrochloride
  • Acetic acid (the main ingredient in white household vinegar)

Purpose
Work together to help keep the vaccine molecules stable while the vaccine is manufactured, frozen, shipped, and stored until it is ready to be given to a vaccine recipient.

Ingredients that are NOT used in COVID-19 vaccines

The above table lists ALL ingredients in the Moderna COVID-19 Vaccine. There are NO ingredients in this vaccine beyond what is listed in the table. The Moderna COVID-19 Vaccine has

  • No preservatives like thimerosal or mercury or any other preservatives.
  • No antibiotics like sulfonamide or any other antibiotics.
  • No medicines or therapeutics like ivermectin or any other medications.
  • No tissues like aborted fetal cells, gelatin, or any materials from any animal.
  • No food proteins like eggs or egg products, gluten, peanuts, tree nuts, nut products, or any nut byproducts (COVID-19 vaccines are not manufactured in facilities that produce food products).
  • No metals like iron, nickel, cobalt, titanium, rare earth alloys, or any manufactured products like microelectronics, electrodes, carbon nanotubes or other nanostructures, or nanowire semiconductors.
  • No latex. The vial stoppers used to hold the vaccine also do not contain latex.

Possible Side Effects

In the arm where you got the shot:

  • Pain
  • Redness
  • Swelling

Throughout the rest of your body:

  • Tiredness
  • Headache
  • Muscle pain
  • Chills
  • Fever
  • Nausea

These side effects happen within a day or two of getting the vaccine. They are normal signs that your body is building protection and should go away within a few days.

Other Authorized and Recommended COVID-19 Vaccines in the United States.

You should get a COVID-19 vaccination as soon as possible. All currently authorized and recommended COVID-19 vaccines are safe and effective, and CDC does not recommend one vaccine over another.

CDC does not recommend mixing products for an initial 2-dose vaccine series or additional doses. Mixing and matching COVID-19 vaccines is allowed for booster shots.

Safety Data Summary

  • In clinical trials, reactogenicity symptoms (side effects that happen within 7 days of getting vaccinated) were common but were mostly mild to moderate. Few people had reactions that affected their ability to do daily activities.
  • Side effects throughout the body (such as fever, chills, tiredness, and headache) were more common after the second dose of the vaccine.
  • Cases of myocarditis and pericarditis in adolescents and young adults have been reported more often after getting the second dose than after the first dose of one of the two mRNA COVID-19 vaccines, Pfizer-BioNTech or Moderna. These reports are rare and the known and potential benefits of COVID-19 vaccination outweigh the known and potential risks, including the possible risk of myocarditis or pericarditis.
  • CDC will continue to provide updates as we learn more about the safety of the Moderna vaccine in real-world conditions.

Learn more about vaccine safety monitoring after a vaccine is authorized or approved for use.

How Well the Vaccine Works

  • Based on evidence from clinical trials, in people aged 18 years and older, the Moderna vaccine was 94.1% effective at preventing laboratory-confirmed COVID-19 infection in people who received two doses and had no evidence of being previously infected.
  • The vaccine was also highly effective in clinical trials at preventing COVID-19 among people of diverse age, sex, race, and ethnicity categories and among people with underlying medical conditions.
  • CDC will continue to provide updates as we learn more about how well the Moderna vaccine works in real-world conditions.

Clinical Trial Demographic Information

Clinical trials for the Moderna vaccine included people from the following racial, ethnic, age, and sex categories:

Race

  • 79% White
  • 10% African American
  • 5% Asian
  • <3% other races/ethnicities
  • <1% American Indian or Alaska Native
  • <1% Native Hawaiian or Other Pacific Islander

Ethnicity

  • 79% not Hispanic or Latino
  • 20% Hispanic or Latino
  • 1% unknown

Sex

  • 53% male
  • 47% female

Age

  • 75% 18 through 64 years
  • 25% 65 years and older

Twenty-two (22%) of people who participated in the clinical trials had at least one condition that put them at risk of severe illness from COVID-19. The most frequent underlying medical conditions among participants were lung disease, heart disease, obesity, diabetes, liver disease, or HIV infection. Four percent (4%) of participants had two or more high-risk conditions.
Most people who participated in the trials (82%) were considered to have an occupational risk of exposure, with 25% of them being healthcare workers.

hand holding medical light icon

For Healthcare Workers

Moderna COVID-19 Vaccine: General information, schedule and administration overview.