COVID-19 MRNA (Pfizer) Vaccine Side Effects

Medically reviewed by Drugs.com. Last updated on Mar 29, 2024.

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

Important warnings This medicine can cause some serious health issues

Intramuscular route (suspension)

Although the licensed vaccine (Comirnaty®) is FDA-approved in patients aged 16 or older for 2 doses , Pfizer-BioNTech COVID-19 vaccine is an unapproved product authorized for emergency use in individuals aged 12 through 15 years and to provide a third dose to individuals aged 12 years or older who are solid organ transplant recipients or have an equivalent level of immunocompromise.

Serious side effects

Along with its needed effects, COVID-19 mRNA (Pfizer) vaccine 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:

More common side effects

• chills
• diarrhea
• fever
• headache
• irritability
• joint or muscle pain
• swollen, painful, or tender lymph glands in the neck, armpit, or groin
• unusual tiredness or weakness

Less common side effects

• nausea
• vomiting

Rare side effects

• decreased appetite
• general feeling of discomfort or illness
• pain in the arms
• rash

Incidence not known

• anxiety
• blue or pale skin
• chest discomfort or tightness
• chest pain, possible moving to the left arm, neck, or shoulder
• cough
• difficulty swallowing
• dizziness
• fainting
• fast heartbeat
• large, hive-like swelling on face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
• puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
• trouble breathing

Other side effects

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:

More common side effects

• pain, redness, or swelling at the injection site

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, headache, and myalgia.^[Ref]

Cardiovascular

• Postmarketing reports: Myocarditis, pericarditis^[Ref]

Dermatologic

• Postmarketing reports: Angioedema, erythema multiforme, pruritus, skin rash, urticaria^[Ref]

Gastrointestinal

• Very common (10% or more): Diarrhea (up to 13.7%)
• Common (1% to 10%): Vomiting
• Uncommon (0.1% to 1%): Nausea^[Ref]

Hematologic

• Uncommon (0.1% to 1%): Lymphadenopathy^[Ref]

Hypersensitivity

• Postmarketing reports: Anaphylaxis, severe allergic reactions^[Ref]

Local

• Very common (10% or more): Injection site pain (up to 79.4%)
• Common (1% to 10%): Injection site redness, injection site swelling^[Ref]

Metabolic

• Uncommon (0.1% to 1%): Decreased appetite^[Ref]

Musculoskeletal

• Very common (10% or more): Myalgia (up to 33.7%), new/worsened muscle pain (up to 31.4%), arthralgia (up to 23.5%), new/worsened joint pain (up to 16.7%)
• Common (1% to 10%): Extremity pain (arm)
• Frequency not reported: Joint pain, muscle pain^[Ref]

Nervous system

• Very common (10% or more): Headache (up to 47.6%)
• Frequency not reported: Bell's palsy, facial paralysis
• Postmarketing reports: Dizziness, hypoesthesia, paresthesia^[Ref]

Bell's palsy was mild to moderate in severity, began 3 to 48 days after the last dose, included facial paralysis and facial paresis, and typically lasted 3 to 68 days. This side effect was reported in 4 participants who received the vaccine and 2 patients who received a placebo, but a causal relationship to the vaccine could not be made.^[Ref]

Other

• Very common (10% or more): Fatigue (up to 64.3%), use of antipyretic/pain medication (up to 46.7%), chills (up to 31.6%)
• Common (1% to 10%): Fever (at least 38C)
• Uncommon (0.1% to 1%): Malaise^[Ref]

Further information

COVID-19 mRNA (Pfizer) vaccine 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.

Some side effects may not be reported. You may report them to the FDA.

Medical Disclaimer