Comirnaty Side Effects

Generic name: COVID-19 mRNA (Pfizer) vaccine

Medically reviewed by Drugs.com. Last updated on Dec 19, 2024.

Note: This document provides detailed information about Comirnaty Side Effects associated with COVID-19 mRNA (Pfizer) vaccine. Some dosage forms listed on this page may not apply specifically to the brand name Comirnaty.

Applies to COVID-19 mRNA (Pfizer) vaccine: intramuscular suspension.

Precautions

Be sure to notify your doctor of any side effects (eg, feeling faint, especially in teenagers) that occur after you receive this vaccine.

Fainting may occur after you receive this vaccine. Your doctor may want you to be observed after you get the injection to prevent and manage fainting.

This vaccine may cause serious allergic reactions, including anaphylaxis, which can be life-threatening and requires immediate medical attention. Tell your doctor right away if you have a rash, itching, a fast heartbeat, trouble breathing, trouble swallowing, or any swelling of your hands, face, or mouth after receiving the vaccine.

This vaccine may increase your risk of serious heart problems (eg, myocarditis, pericarditis), especially after you receive the second dose. Check with your doctor right away if you have anxiety, blue or pale skin, chest pain, possibly moving to the left arm, neck, or shoulder, fever, chills, a fast heartbeat, trouble breathing, or unusual tiredness or weakness.

This vaccine may not protect everyone who receives it. This vaccine will not treat symptoms of COVID-19 infection if you already have the disease. It is very important that you take precautions to reduce the risk of COVID-19.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

Serious side effects of Comirnaty

Along with its needed effects, COVID-19 mRNA (Pfizer) vaccine (the active ingredient contained in Comirnaty) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur while taking COVID-19 mRNA (Pfizer) vaccine:

Other side effects of Comirnaty

Some side effects of COVID-19 mRNA (Pfizer) vaccine may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

For healthcare professionals

Applies to COVID-19 mRNA (Pfizer) vaccine: intramuscular suspension.

General adverse events

The most commonly reported side effects included injection site pain, fatigue, and headache.^[Ref]

Cardiovascular

• Postmarketing reports: Myocarditis, pericarditis^[Ref]

Dermatologic

• Frequency not reported: Hyperhidrosis, night sweats
• Postmarketing reports: Pruritus, rash, urticaria^[Ref]

Gastrointestinal

• Very common (10% or more): Diarrhea (up to 11.1%)
• Common (1% to 10%): Vomiting
• Frequency not reported: Nausea^[Ref]

Hematologic

• Common (1% to 10%): Lymphadenopathy^[Ref]

Hypersensitivity

• Postmarketing reports: Anaphylaxis, angioedema, other hypersensitivity reactions (e.g., pruritus, rash, urticaria), severe allergic reactions^[Ref]

Local

• Very common (10% or more): Injection site pain (up to 90.5%), injection site swelling (up to 11.8%), injection site redness (up to 10.4%)
• Postmarketing reports: Extremity (arm) pain^[Ref]

Metabolic

• Frequency not reported: Decreased appetite^[Ref]

Musculoskeletal

• Very common (10% or more): Chills (up to 49.2%), muscle pain (up to 45.5%), new/worsened muscle pain (up to 39.3%), joint pain (up to 27.5%), new/worsened joint pain (up to 23.8%)^[Ref]

Nervous system

• Very common (10% or more): Headache (up to 75.5%)
• Frequency not reported: Bell's palsy/facial paralysis, lethargy
• Postmarketing reports: Dizziness, syncope^[Ref]

Other

• Very common (10% or more): Fatigue (up to 77.5%), use of antipyretic or pain medication (up to 50.8%), fever (up to 24.3%)
• Frequency not reported: Asthenia, malaise^[Ref]

See also:

Further information

Comirnaty side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

Medical Disclaimer