Important update: Healthcare facilities
CDC has updated select ways to operate healthcare systems effectively in response to COVID-19 vaccination. Learn more
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

General Information

Manufacturer: ModernaTX, Inc.

Number of Shots: 2 shots, 28 days apart
Moderately or severely immunocompromised people should get an additional primary shot (third dose) at least 28 days after their second shot.

Booster Shot: People ages 18 years and older who received a Moderna primary series should get a booster shot at least 5 months after completing their primary series. CDC recommends getting a booster dose of either Pfizer-BioNTech or Moderna (mRNA COVID-19 vaccines) in most situations.

Type of Vaccine: mRNA

How Given: Shot in the muscle of the upper arm

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

Name: mRNA-1273

Who Should Get Vaccinated
Who Should NOT Get Vaccinated
  • If you have had a severe allergic reaction to any ingredient in an mRNA COVID-19 vaccine (such as polyethylene glycol), you should not get an mRNA COVID-19 vaccine (Moderna or Pfizer-BioNTech).
  • If you had a severe 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).
  • A severe allergic reaction can cause a rapid heartbeat, difficulty breathing, swelling of the throat, or a generalized rash or hives. A person with a severe allergic reaction needs to be treated with epinephrine (often given as an EpiPen®) and should seek immediate medical attention.

If you cannot 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 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 the vaccine ingredients, just as it would discard any substance 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 are normal signs that your body is building protection and should go away within a few days. Talk to a doctor about taking over-the-counter medicine, such as ibuprofen, acetaminophen, aspirin (only for people ages 18 years or older), or antihistamines for any pain or discomfort experienced after getting vaccinated.

Other authorized or approved COVID-19 vaccines in the United States and eligible age groups

You should get a COVID-19 vaccination as soon as possible. All currently approved or authorized COVID-19 vaccines are safe and effective. However, CDC recommends that people who are starting their vaccine series or getting a booster dose get either Pfizer-BioNTech or Moderna (mRNA COVID-19 vaccines). The mRNA vaccines are preferred over Johnson & Johnson’s Janssen COVID-19 vaccine in most circumstances.

CDC does not recommend mixing products for a two-dose primary series or additional primary doses.  For a booster dose, adults ages 18 years and older may choose which vaccine product they get. CDC recommends either Pfizer-BioNTech or Moderna (mRNA COVID-19 vaccines) in most circumstances. Although mRNA vaccines are preferred, the J&J/Janssen COVID-19 vaccine may be considered in some situations.

Safety Data Summary

  • Side effects that happen within 7 days of getting vaccinated are common but are mostly mild to moderate. Some people have reactions that affect their ability to do daily activities.
  • Side effects throughout the body (such as fever, chills, tiredness, and headache) are more common after the second dose of the vaccine.
  • Rare cases of myocarditis and pericarditis in adolescents and young adults have been reported after receipt of one of the two mRNA COVID-19 vaccines, Pfizer-BioNTech or Moderna. These cases occur more often after getting the second dose than after the first dose of one of these vaccines. 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.

All FDA-approved or authorized COVID-19 vaccines have undergone and continue to undergo the most intensive safety monitoring in U.S. history. This monitoring includes using both established and new safety monitoring systemspdf icon to make sure that COVID-19 vaccines are safe.

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 ages 18 years and older, the Moderna COVID-19 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 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.
  • Evidence shows mRNA COVID-19 vaccines offer similar protection in real-world conditions as they have in clinical trial settings―reducing the risk of COVID-19, including severe illness, by 90% or more among people who are fully vaccinated.
  • CDC will continue to provide updates as we learn more.
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For Healthcare Workers

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