COVID-19 Vaccine, mRNA

Brand Name(s): Comirnaty®, Spikevax®, Moderna COVID-19 Vaccine®, Pfizer-BioNTech COVID-19 Vaccine®

Why get vaccinated?

COVID-19, mRNA vaccine can prevent COVID-19 disease.

COVID-19 disease is caused by a coronavirus called SARS-CoV-2. You can get COVID-19 through contact with another person who has the virus. It is predominantly a respiratory (lung) illness, but it can also affect other organs.

People with COVID-19 have had a wide range of symptoms reported, ranging from mild symptoms to severe illness leading to death. Symptoms may appear 2 to 14 days after exposure to the virus. Symptoms may include: fever, chills, cough, shortness of breath, fatigue, muscle or body aches, headache, loss of taste or smell, sore throat, congestion, runny nose, nausea, vomiting, or diarrhea.

What is COVID-19, mRNA vaccine?

CDC recommends everyone 5 years of age and older receive the newest formulation of the COVID-19 vaccine, mRNA. Children 6 months through 4 years of ages should receive 1 to 3 doses of the newest formulation of the COVID-19 vaccine, mRNA depending on whether or not they have received any other formulations of the COVID-19 vaccine and the number of doses they have received. Any individual who has a weakened immune system due to other medications or other conditions may receive additional doses.

There are many variants of the COVID-19 virus and the vaccine will need to be reformulated periodically to cover the current circulating variants.

In clinical trials, the COVID-19 vaccine, mRNA has been shown to reduce risk COVID-19 disease following infection with SARS-CoV-2 virus . How long you are protected against serious outcomes from COVID-19 infection is currently unknown.

COVID-19 vaccine, mRNA may be given at the same time as many other vaccines.

The COVID-19 vaccine, mRNA does not contain SARS-CoV-2 and cannot give you COVID-19.

What should you tell the person who is giving the vaccine?

Tell your vaccine provider if you:

  • have had an allergic reaction after a previous dose of COVID-19 vaccine, mRNA, or have had any severe, life-threatening allergies.

  • have had myocarditis (inflammation of the heart muscle) or pericarditis (inflammation of the lining outside the heart).

  • have a fever.

  • have a bleeding disorder or are taking a blood thinner such as warfarin (Coumadin, Jantoven).

  • have a weakened immune system or are on a medicine that affects your immune system.

  • are breast-feeding.

  • have received another COVID-19 vaccine.

  • have ever fainted in association with an injection.

In some cases, your health care provider may decide to postpone COVID-19 vaccine, mRNA to a future visit.

Safety of COVID-19 vaccine, mRNA during pregnancy is not known but COVID-19 infection can have adverse outcomes during pregnancy. Pregnant patients should talk to their doctors about risks and benefits of receiving a COVID-19, mRNA vaccine during pregnancy.

People with minor illnesses, such as a cold, may be vaccinated. People who are moderately or severely ill should usually wait until they recover before getting COVID-19 vaccine, mRNA.

Your health care provider can give you more information.

What are the risks from COVID-19, mRNA vaccine?

Side effects that have been reported with the COVID-19 vaccine, mRNA include:

  • non-severe allergic reactions such as rash, itching, or hives

  • injection site pain, swelling, and redness

  • tiredness

  • headache

  • muscle pain

  • chills

  • joint pain

  • fever

  • nausea

  • feeling unwell

  • swollen lymph nodes

  • decreased appetite

  • diarrhea

  • vomiting

  • arm pain

  • fainting at the time you receive your injection

People sometimes faint after medical procedures, including vaccination. Tell your provider if you feel dizzy or have vision changes or ringing in the ears.

What if there is a serious reaction?

There is a remote chance that the COVID-19 vaccine, mRNA could cause a severe allergic reaction. A severe allergic reaction would usually occur within a few minutes to one hour after getting a dose of the COVID-19 vaccine, mRNA.

Signs of a severe allergic reaction can include:

  • difficulty breathing

  • swelling of your face and throat

  • a fast heartbeat

  • a bad rash all over your body

  • dizziness and weakness

Myocarditis and pericarditis have occurred in some people who have received the COVID-19 vaccine, mRNA, more commonly in males under 40 years of age than among females and older males. In most of these people, symptoms began within a few days after getting the second dose of the COVID-19 vaccine, mRNA. The chance of having this occur is very low.

You should seek medical attention right away if you have any of the following symptoms after receiving the COVID-19 vaccine, mRNA:

  • chest pain

  • shortness of breath

  • feelings of having a fast-beating, fluttering, or pounding heart

For other signs that concern you, call your health care provider.

Adverse reactions should be reported to the Vaccine Adverse Event Reporting System (VAERS). Your health care provider will usually file this report, or you can do it yourself. Visit the VAERS website at or call 1-800-822-7967. VAERS is only for reporting reactions, and VAERS staff members do not give medical advice.

The National Vaccine Injury Compensation Program

The National Vaccine Injury Compensation Program (VICP) is a federal program that was created to compensate people who may have been injured by certain vaccines. Claims regarding alleged injury or death due to vaccination have a time limit for filing, which may be as short as two years. Visit the VICP website at or call 1-800-338-2382 to learn about the program and about filing a claim.

How can I learn more?

This report on medications is for your information only, and is not considered individual patient advice. Because of the changing nature of drug information, please consult your physician or pharmacist about specific clinical use.

The American Society of Health-System Pharmacists, Inc. represents that the information provided hereunder was formulated with a reasonable standard of care, and in conformity with professional standards in the field. The American Society of Health-System Pharmacists, Inc. makes no representations or warranties, express or implied, including, but not limited to, any implied warranty of merchantability and/or fitness for a particular purpose, with respect to such information and specifically disclaims all such warranties. Users are advised that decisions regarding drug therapy are complex medical decisions requiring the independent, informed decision of an appropriate health care professional, and the information is provided for informational purposes only. The entire monograph for a drug should be reviewed for a thorough understanding of the drug's actions, uses and side effects. The American Society of Health-System Pharmacists, Inc. does not endorse or recommend the use of any drug. The information is not a substitute for medical care.

AHFS ® Patient Medication Information™. © Copyright, 2023. The American Society of Health-System Pharmacists ® , 4500 East-West Highway, Suite 900, Bethesda, Maryland. All Rights Reserved. Duplication for commercial use must be authorized by ASHP.

Selected Revisions: October 15, 2023.