Spikevax Side Effects

Generic name: COVID-19 mRNA (Moderna) vaccine

Medically reviewed by Drugs.com. Last updated on Feb 10, 2025.

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

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

Precautions

Be sure to notify your doctor of any side effects that occur after you receive this vaccine.

This vaccine may cause serious allergic reactions, including anaphylaxis, which can be life-threatening and require 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.

Fainting may occur after you receive this vaccine. You may also have vision changes, numbness or tingling in your arms, hands, or feet, or jerky movements of the arms and legs. Your doctor may want you to be observed after you get the injection to prevent and manage fainting.

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 Spikevax

Along with its needed effects, COVID-19 mRNA (Moderna) vaccine (the active ingredient contained in Spikevax) 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 (Moderna) vaccine:

Other side effects of Spikevax

Some side effects of COVID-19 mRNA (Moderna) 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:

See also:

For healthcare professionals

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

General adverse events

The most common adverse reactions reported in adults and adolescents (12 years and older) after administration included injection site pain, fatigue, headache, myalgia, arthralgia, chills, axillary swelling/tenderness, nausea/vomiting, and injection site swelling.

This formulation is intended for adults and adolescents (12 years and older); therefore, the adverse reactions and rates listed are specific for this patient population.

For adverse reactions reported in infants and children (aged 6 months through 11 years), the SIDE EFFECTS section for SARS-CoV-2 (COVID-19) mRNA-LNP vaccine (cvx 311) should be consulted.^[Ref]

Cardiovascular

• Frequency not reported: Probable myocarditis
• Postmarketing reports: Myocarditis, pericarditis

Dermatologic

• Common (1% to 10%): Rash
• Frequency not reported: Angioedema, erythema nodosum
• Postmarketing reports: Urticaria

Angioedema included facial swelling.

Gastrointestinal

• Very common (10% or more): Nausea/vomiting (up to 24.2%)

Grade 3 and 4 nausea/vomiting have been reported in up to 0.3% and up to 0.7% of patients, respectively.

Hematologic

• Common (1% to 10%): Lymphadenopathy-related events

Lymphadenopathy-related events included lymphadenopathy, lymphadenitis, lymph node pain, vaccination-site lymphadenopathy, injection-site lymphadenopathy, and axillary mass.

Hypersensitivity

• Frequency not reported: Hypersensitivity events
• Postmarketing reports: Anaphylaxis

Hypersensitivity events included injection site rash and injection site urticaria.

Local

• Very common (10% or more): Local pain (up to 93.5%), injection site pain (up to 90.6%), local axillary swelling/tenderness (up to 39.5%), local swelling/hardness (up to 20.7%), local erythema/redness (up to 19.9%), injection site swelling (up to 13.3%), local adverse reactions
• Common (1% to 10%): Injection site swelling, injection site erythema, delayed injection site reactions

Grade 3 local adverse reactions included pain (up to 6.1%), axillary swelling/tenderness (up to 1.9%), swelling/hardness (greater than 100 mm: Up to 2.7%), and erythema/redness (greater than 100 mm: Up to 2.9%).

Delayed injection site reactions included pain, erythema, and swelling.

Musculoskeletal

• Very common (10% or more): Myalgia (up to 61.7%), arthralgia (up to 45.6%)

Grade 3 myalgia has been reported in up to 10.1% of patients. Grade 3 and 4 arthralgia have been reported in up to 5.9% and less than 0.1% of patients, respectively.

Nervous system

• Very common (10% or more): Headache (up to 70.5%)
• Frequency not reported: Facial paralysis
• Postmarketing reports: Syncope, febrile seizures

Grade 3 and 4 headache have been reported in up to 7.5% and less than 0.1% of patients, respectively.

Facial paralysis included Bell's palsy.

Other

• Very common (10% or more): Fatigue (up to 70.1%), use of antipyretic or pain medication (up to 57.3%), chills (up to 49%), axillary swelling/tenderness (up to 27.8%), fever (up to 19%)
• Frequency not reported: Herpes zoster

Grade 3 and 4 fatigue have been reported in up to 10.7% and less than 0.1% of patients, respectively. Grade 3 chills has been reported in up to 1.5% of patients. Grade 3 and 4 fever have been reported in up to 2.7% and up to 0.3% of patients, respectively.

Frequently asked questions

• COVID-19 vaccines and variants: What you should know

Further information

Spikevax 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